Frequent Variants Research Articles

Endocrine Perspective of Cutaneous Lichen Amyloidosis: RET-C634 Pathogenic Variant in Multiple Endocrine Neoplasia Type 2

Background: Medullary thyroid carcinoma (MTC), the third most frequent histological type of thyroid malignancy, may be found isolated or as part of multiple endocrine neoplasia type 2 (MEN2). One particular subtype of this autosomal dominant-transmitted syndrome includes an association with cutaneous lichen amyloidosis, although, generally, a tide genotype–phenotype correlation is described in patients who carry RET proto-oncogene pathogenic variants. Methods: Our objective was to provide an endocrine perspective of a case series diagnosed with RET-positive familial MTC associated with cutaneous primary lichen amyloidosis amid the confirmation of MEN2. Six members of the same family had cutaneous lesion with different features (from hyperpigmented, velvety to red/pink appearance) and four of them harbored a RET pathogenic variant at 634 codon (exon 11): c.1900T>G, p.634G (TGC634CGC). Results: All six patients were females with the lesion at the interscapular region. Except for two women, four of these subjects were investigated and had MTC (three of them with postoperatory confirmation). The youngest affected individual was 6 years old. The three adult females were confirmed with RET pathogenic variant during their 30s, while the girl underwent the familial screening as a newborn. None of them had primary hyperparathyroidism until the present time, except for one subject, and two out of the three adults also had bilateral pheochromocytoma. Notably, all patients were rather asymptomatic from the endocrine perspective at the moment when endocrine tumor/cancer was confirmed, and the skin was progressively affected a few years before the actual MEN2 confirmation. Conclusions: This case series highlights the following key message: awareness of the dermatologic findings in MTC/MEN2 patients is essential since lesions such as cutaneous lichen amyloidosis might represent the skin signature of the endocrine condition even before the actual endocrine manifestations. These data add to the limited published reports with respect to this particular presentation, noting the fact that RET-C634 is the most frequent pathogenic variant in MEN2-associated lichen amyloidosis; females are more often affected; the interscapular region is the preferred site; the age of diagnosis might be within the third decade of life, while we reported one of the youngest patients with the lesion. The same RET pathogenic variant is not associated with the same dermatologic features as shown in the vignette. The same RET mutation does not mean that all family members will present the same skin anomaly.

Genetic testing in pulmonary hypertension in adults and children

Abstract Pathogenic genetic variants have been found in patients with different forms of pulmonary arterial hypertension (PAH). Our aim was to define the genetic background of patients with idiopathic PAH (IPAH), heritable PAH (HPAH), pulmonary veno-occlusive disease (PVOD) and PAH associated with congenital heart disease (PAH-CHD); both in adult and pediatric age. REHAP and REHIPED are Spanish, voluntary, multicenter registries that include patients with PAH. REHAP started in 2007 and includes patients over 18 years of age. REHIPED started in 2009 and collects patients between 2 months and 18 years of age. Patients with IPAH, HPAH, PVOD and PAH-CHD who have undergone a genetic testing were included. 413 adults and 122 children were analyzed. From 2011, Sanger sequencing and multiplex ligation-dependent probe amplification were used to detect genetic variants in the BMPR2, TBX4, and KCNK3 genes. Since 2014, a next generation sequencing (NGS) panel of 21 genes was applied. In 2017 this panel was expanded to cover 35 genes, and in 2019, it was expanded to 37 genes. Since 2020, whole-exome sequencing has been applied for the previously followed-up patients without known pathogenic/likely pathogenic (P/LP) genetic variants, and for each incident case. There was a statistically significant difference (p 0.031) in the etiologies among adults and children. The etiologies in adults were 242 (59%) IPAH, 25 (6%) HPAH, 83 (20%) PAH-CHD, 63 (15%) PVOD. The etiologies in children were 66 (54%) IPAH, 8 (7%) HPAH, 38 (31%) PAH-CHD, and 10 (8%) PVOD. The genetic testing had a variant in 121 (29%) adults (56% pathogenic, 9% likely pathogenic, 32% VUS) and 63 (52%) children (65% pathogenic, 16% LP, 19% VUS) (adults vs children p < 0.001). BMPR2 was the most frequent variant in both populations, followed by EIF2AK4. Patients with HAPH and PVOD are more likely to have a genetic variant, while PAH-CHD are the less likely to have one; both in adults and children (p<0.001). The etiology was reclassified after the genetic testing in 13% adults and 19% children (p 0.08); including 6 adults and 4 children initially classified as IPAH and then diagnosed of PVOD when a P/LP variant was found in EIF2AK4. Also, 5 children were initially diagnosed as IPAH and then reclassified as multisystemic disorders (4 NFU1 and 1 MECP2) In conclusion, a significant number of patients with PAH have a variant in genetic testing, especially if they are diagnosed in pediatric age. BMPR2 is the most frequent variant in our cohort, followed by EIF2AK4. Knowing the genetic background of our patients enables a better classification and understanding of the disease. This is especially important in patients initially diagnosed of PAHI who are then classified as PVOD. Also, knowing the genetic background may help develop new treatments in the future.

Variant reclassification over time decreases the level of diagnostic uncertainty in monogenic obesity: Experience from two centres.

The diagnosis of monogenic obesity is burdened by frequent variants of uncertain significance (VUS). We describe our real-life approach of variant reassessment over time and we assess whether inconclusive variants are decreasing in monogenic obesity. We tested for monogenic obesity (genes: LEPR, POMC, ADCY3, PCSK1, CARTPT, SIM1, MRAP2, LEP, NTRK2, BDNF, KSR2, MAGEL2, SH2B1, MC4R, MC3R) in 101 children/adolescents (11.7 [7.3-13.7] years, 3.6 [3.3-4.0] z-BMI) in Verona and 183 (11.3 [8.4-12.2] years, 3.2 [2.7-3.9] z-BMI) in Naples from January 2020 to February 2023. In March-July 2024 we reassessed the baseline variants by updated software interpretation and literature renavigation. We initially found 20 VUS, 4 Likely Pathogenic (LP), 5 Likely Benign (LB) and 1 benign variant in 33 individuals. At follow-up, 6 VUS were reclassified as benign/LB, one LP as pathogenic and 3 LB as benign. Overall, 10/30 variants (6/18 in Verona, 3/11 in Naples and a variant found in both centres) were reclassified, leading to a less uncertain report for 13 of 33 variant-carrying patients. Monogenic obesity was diagnosed in 3 probands in Verona and 4 in Naples, carrying variants at MC4R or NTRK2. Our variant reassessment was effective to improve classification certainty for the 39% of patients and suggested that the molecular diagnosis of monogenic obesity is becoming more accurate over time.

A case of rapidly progressive hair loss due to azathioprine, and the prevalence of NUDT15 variants among Japanese patients with autoimmune blistering diseases: A single-center retrospective observational study.

Autoimmune blistering diseases (AIBDs), classified into pemphigus and pemphigoid, consist of relatively rare skin disorders caused by autoantibodies that target desmosomal and hemidesmosomal proteins, respectively. Although systemic corticosteroids are used as a first-line treatment for AIBDs, azathioprine is frequently co-administered as a steroid-sparing agent. Azathioprine is metabolized into thioguanine nucleotides (TGNs) which are its major active metabolites. The enzyme nudix hydrolase 15 (NUDT15) plays a key role in regulating TGNs. Serious side effects of azathioprine, including leukopenia and alopecia, are known to be particularly problematic in individuals with NUDT15 variants. The single-nucleotide polymorphism c.415C >T (p.Arg139Cys) is one of the most frequent NUDT15 variants associated with severe thiopurine toxicity. Recently, we treated a case of pemphigus vulgaris in a patient with NUDT15 variants in which the patient developed rapidly progressive diffuse hair loss and myelosuppression while receiving azathioprine. Previous reports on NUDT15 polymorphisms mainly focused on patients with inflammatory bowel disease or hematological malignancies, and the prevalence of NUDT15 polymorphisms remains unknown in AIBDs. This highlights the urgent need for research on NUDT15 polymorphisms in AIBDs to achieve a better understanding of the genetic factors influencing adverse reactions to azathioprine. To clarify the prevalence of NUDT15 variants in Japanese patients with AIBDs, we retrospectively reviewed the medical records of 78 patients with AIBDs (26 with bullous pemphigoid, 26 with pemphigus vulgaris, 17 with pemphigus foliaceus, and nine with other AIBDs) who had come to Hokkaido University Hospital between 2018 and 2023. The frequencies of NUDT15 variants of Arg/Arg, Arg/Cys, and Cys/Cys in these patients were approximately 72%, 23%, and 5%, respectively. Our findings indicate a prevalence of NUDT15 variants in AIBD patients that is similar to the prevalences of previous studies on patients with other diseases. These results emphasize the importance of screening for NUDT15 variants prior to initiating azathioprine treatment in Japanese patients with AIBDs.

A retrospective study on biotinidase deficiency: analysis of the Eastern Anatolia region patient cohort

ABTRACT This study retrospectively reviews individuals diagnosed with biotinidase deficiency in Eastern Anatolia to analyze the genetic variants and their relationship with biotinidase activity levels. The research focuses on determining the percentage impact of different variants on enzyme activity. The study included 357 patients who presented to Erzurum City Hospital with symptoms of biotinidase deficiency between 2018 and 2023 and were referred to the medical genetics department. Biotinidase enzyme levels were determined using spectrophotometric and colorimetric techniques, while Sanger sequencing analyzed the four exons and intron boundaries of the BTD gene. In the analysis of 357 patients (181 boys, 176 girls), the most frequent variant was c.1270G > C | p.Asp424His. Biotinidase enzyme activity was above 30% in 97.3% of patients with a homozygous p.D424His mutation. The mutations that caused the most significant decrease in enzyme activity were c.410G > A p.Arg137His, c.38_delinsTCC p.Cys13phefs*36, and c.1535C > T p.Thr512Met. Hearing loss (4 patients) and optic atrophy (1 patient) were mainly observed in patients with the c.38_delinsTCC mutation (homozygous or heterozygous). Most patients were asymptomatic, and mild symptoms were effectively prevented with biotin treatment. This study provides a detailed analysis of genetic diversity and clinical presentation in biotinidase deficiency cases in Eastern Anatolia, demonstrating the efficacy of biotin treatment. It highlights the significant role of genetic variants in phenotypic diversity and the need for personalized treatment, calling for further genetic research to enhance understanding of variant diversity and its impact on enzyme activity.

Molecular analysis of BRCA1 and BRCA2 genes in La Rioja (Spain): five new variants.

To study BRCA1/2 gene variants in La Rioja in the northcentral area of Spain. We performed a molecular analysis of BRCA1 and BRCA2 in 642 individuals from 427 different families from June 2008 to December 2019. We identified 71 families with pathogenic variants in these genes, 32 families with BRCA1 variants and 39 families with BRCA2 variants. The pathogenic variants c.959delG in BRCA1 and c.1363_1369delTCAGAGA, c.1397dupA, c.4234_4236delACTinsC and c.8387delC in BRCA2 have not been previously described. The c.81-2A > T variant in BRCA1, detected in two unrelated families, has not been reported previously in the Spanish population. Two large genomic deletions were found in the BRCA1 gene in exons (Ex) 23-24 and Ex1A-1B-2, and one deletion was found in the BRCA2 gene in Ex2. The pathogenic variant c.5123C > A in BRCA1 was detected in 8 unrelated families and was the most frequent pathogenic variant in our population. The c.6024dupG mutation in BRCA2 was detected in 6 unrelated families; the c.2808_2011delACAA mutation in BRCA2 was found in 5 different families; the c.211A > G mutation in BRCA1 was found in three different families; and the c.68_69delAG, c81-2A > T, c.4038_4039delAA, and c.5266dupC variants in BRCA1 and the c.2457delA, c.2701delC, c.5116_5119delAATA, c.6275delTT, c.7558C > T and c.7617 + 1G > A variants in BRCA2 were found in two different families. The spectrum of pathogenic variants in the BRCA1/2 genes in La Rioja is similar to that in other Spanish regions, with some unique characteristics. The pathogenic c.6024dupG variant in the BRCA2 gene was detected in a large number of families and could have a founding effect in the Ebro riverside areas in the regions of La Rioja and Navarra. Not applicable.

Analysis of the regional distribution differences of common variations of the MMACHC gene in cblC methylmalonic acidemia patients

Objective: To analyze regional differences in MMACHC gene variations among patients with cblC-type methylmalonic acidemia (MMA) in China and to explore the relationship between these variations and neonatal screening, biochemical markers and prognosis. Methods: Retrospective case summary. Clinical and laboratory data, including general condition, biochemical markers and genetic analysis, were collected from 1 859 cblC MMA patients from 2005 to 2023. Patients were divided into 7 groups according to their regions: north China, northeast China, east China, central China, south China, southwest China and northwest China. They were also classified into neonatal screening and non-neonatal screening groups. Mann-Whitney U and Kruskal-Wallis tests were used to compare biochemical marker levels. In contrast, the Chi-square test was applied to compare MMACHC gene variant frequencies, neonatal screening proportion, onset age and prognosis between groups. Results: Among 1 859 cases of cblC MMA, 1 019 were male and 840 were female, with a consultation age of 1.0 (0.1, 5.0) month. A total of 1 787 cases carried compound heterozygous or homozygous variants and only 1 variant site was identified in 72 cases. The 10 most frequent variants were c.609G>A (1 238 cases), c.658_660delAAG (343 cases), c.80A>G (284 cases), c.482G>A (239 cases), c.567dupT (191 cases), c.656_658delAGA (131 cases), c.217C>T (109 cases), c.394C>T (105 cases), c.445_446delTG (51 cases) and c.1A>G (50 cases). The frequency of the c.609G>A was the lowest in northwest China (28.8% (44/154), χ²=-18.42, P<0.05). The frequency of the c.567dupT was the most common in southwest China (25.0% (20/80), χ²=71.70, P<0.001) and c.656_658delAGA had the highest frequency in northeast China (9.3% (19/205), χ²=32.08, P<0.001). Non-missense variants (91.2% (62/68), 88.5% (46/52)) and early-onset patients (90.0% (36/40), 94.4% (34/36)) were both more prevalent in southwest and south China (χ²=14.95, 31.69, both P<0.05). The proportion of neonatal screening was the lowest in south China (22.2% (8/36), χ²=98.48, P<0.05), where the mortality rate was the highest (19.1% (4/21), χ²=38.98, P<0.001). East China exhibited the highest frequency of missense variants (21.5% (339/1 579)), the highest proportion of patients identified through neonatal screening (54.5% (465/853)), and a more significant proportion of patients with good prognosis (36.6% (227/621), χ²=14.57, 93.49, 38.98, all P<0.05). In addition, the c.482G>A variant was more frequent in patients diagnosed by neonatal screening compared to those diagnosed by other methods (8.3% (132/1 586) vs. 5.9% (122/2 060), χ²=7.97, P<0.05). Conclusions: The frequency of MMACHC gene variation varies across different regions. The c.609G>A was least frequent in northwest China, c.567dupT was most common in southwest China, and c.656_658delAGA was most prevalent in northeast China. South China had the lowest neonatal screening rate and the highest mortality. At the same time, east China exhibited the highest frequency of missense variants, the highest proportion of patients identified through neonatal screening and the best prognosis. The c.482G>A variant was more frequent in patients diagnosed by neonatal screening compared to those diagnosed by other methods.

Inverse Shifting-PCR Modified by Capillary Electrophoresis for Detecting F8 int22h and int1h Inversions in Severe Hemophilia A Patients and Probable Carriers.

Globally, intron 22 inversions (Inv22s) of the factor VIII gene (F8) are the most frequent pathogenic variants and account for 45-50% of severe hemophilia A (SHA) cases, while intron 1 inversion (Inv1) explains 1-5% of SHA cases. The detection of both inversions by an inverse shifting-polymerase chain reaction (IS-PCR) is the first choice worldwide for the diagnosis of patients and carriers of SHA. To improve its sensitivity and reproducibility in the visualization of PCR products, we approached the IS-PCR with fluorescent capillary electrophoresis instead of agarose electrophoresis. Based on the original protocol, we modified two primers by 5'-end labeling with FAM™ fluorescent dye for the detection of the PCR products by capillary electrophoresis. Additionally, the "fast enzymes" BclI and T4-Ligase were incorporated for work saving in the genomic digestion and ligation reactions, respectively. Once we accomplished the standardization and verified the reproducibility of the modified IS-PCR method, we applied it for the diagnosis of a cohort of SHA patients and carriers. The modified IS-PCR by fluorescent capillary electrophoresis for PCR product detection is more sensitive than agarose electrophoresis. The method was also improved by using the new rapid enzymes to save time in the whole process.

8034 Putting the Pieces Together: Carney Complex, A Hyper-Rare Congenital Neoplastic Syndrome

Abstract Disclosure: G. Fontanazza: None. A.R. Conforti: None. K. Bird: None. M. Caplan: None. Intro: Carney complex (CNC) is an autosomal dominant disorder characterized by multisystem neoplasia that primarily affects the thyroid, pituitary, and adrenal glands. Its prevalence is not well established, as only 750 cases have been reported worldwide. This condition arises when an inactivating PRKAR1A gene mutation results in dysregulated cell proliferation and tumorigenesis. Complications include the potential for malignant transformation and systemic manifestations, necessitating comprehensive management and ongoing surveillance of disease progression. Case: The patient is a 58-year-old woman who initially presented as a teenager with complaints of hirsutism, truncal obesity, and violaceous abdominal striae. Initial workup revealed a low-dose dexamethasone suppression test that resulted in a non-suppressed cortisol levels. She also had undetectable adrenocorticotropic hormone (ACTH) levels. Imaging revealed no pituitary masses and demonstrated slight bilateral adrenal enlargement without adenomas. Despite these results, she was empirically treated for presumed pituitary-dependent Cushing's disease and received external beam radiation. Despite treatment, she continued to have episodes of hypercortisolism that were apparent clinically and biochemically. Over time, she developed a cardiac myxoma with six cerebrovascular accidents and multiple benign tumors. As an adult, she underwent extensive endocrine evaluation, which revealed urine cortisol excretion that paradoxically rose in response to dexamethasone. ACTH levels were always undetectable, even when she was significantly hypercortisolemic. Genetic testing revealed a homozygous mutation in the melanocortin-2 receptor (MC2R). Accordingly, she elected to have a bilateral adrenalectomy and was started on hydrocortisone and fludrocortisone. Discussion: The patient exhibited ACTH-independent micronodular adrenal hyperplasia and its most frequent variant, primary pigmented nodular adrenocortical disease. Bilateral pigmented nodular hyperplasia is a finding which can occur in association with CNC and cause episodic hypercortisolism. These patients have been shown to respond to dexamethasone with a paradoxical increase in glucocorticoid excretion. While management requires ongoing surveillance, this patient had not been diagnosed until later in life and did not have regular screening. When speculating on the late detection, her story reflects the parable of the blind men and the elephant: endocrinology managed Cushing's disease, cardiology managed atrial myxoma, and oncology managed osteochondromyxomas. Limited perspective with specialized management and an inability to see the whole picture led to prolonged diagnosis with unfortunate sequelae. This report encourages physicians to develop perspective awareness and to consider the entire picture when treating patients. Presentation: 6/2/2024

7673 Genetic Analysis and Clinical Characterization of Patients with Congenital Hypopituitarism Due to Gene Defects

Abstract Disclosure: T.M. Sasson: None. I.J. Arnhold: None. B.B. Mendonca: None. L.R. Carvalho: None. Introduction: Congenital hypopituitarism is characterized by the deficiency of one or more hormones secreted by the anterior pituitary gland. The genetics of this pathology is complex, and the molecular diagnosis is established in approximately 13% of cases. Objectives: The aim of the present study is to characterize the phenotype harboring pathogenic variants causing congenital hypopituitarism. Methods: Among 393 subjects with congenital hypopituitarism followed up at a tertiary health center, 57 subjects (14,5%) were selected due to a confirmed molecular diagnosis by exome in 9 subjects or by gene panel or Sanger sequencing in 48 subjects. This was a retrospective study where data from medical records, clinical, laboratory and radiological characteristics were analyzed. Results: The most frequent variants identified by sequencing analyzes were in the following genes: PROP1 (29.8%), GH1 (22.8%), GHRHR (15.7%), followed by GLI2, OTX2, HESX1, POU1F1, TGIF1, GHRS, CDH2, SATB1, SOX3 e LZTR1. Consanguinity was reported in 50% of cases, and there was the presence of familial cases of short stature in 60%. The average age at the start of follow-up was 11.1 years (11 SD), 40% of them were male and 52.3% had physical stigmata typical of GH deficiency. Regarding hormonal deficiencies, 27 (47%) had isolated Growth Hormone Deficiency (DGHI) and the others, multiple deficiencies. MRI study of the pituitary gland showed some alteration in 66%, 54% of whom had adenohypophysis hypoplasia and 31% had an ectopic or non-visualized neurohypophysis. From 29 patients with IGF-1 levels available, 28 were below the reference range for sex and age. The serum GH peak after the stimulus test was on average 1.28 ng/mL (1.4SD), of these, only 4 cases had GH peak between 3.3 and 5.0 ng/mL and 1 patient with low IGF-1 and an ectopic neurohypophysis had GH peak of 6.0 ng/mL in a glucagon test. Regarding growth, the initial height in z-score was -4.8 and the average growth at the end of the first year of treatment was 10.7cm, with the average height after this period of Z-3.35. The average of final delta target height (final height Z-score minus the target height Z-score) of patients who underwent hormonal treatment was -0,53 (good response = delta &amp;lt;-1.5). Conclusion: In subjects with congenital hypopituitarism and an established molecular diagnosis, the most frequently affected genes were PROP1 and GH1, the great majority presented a stimulated GH peak &amp;lt; 3.3 ng/mL (only one patient had GH &amp;gt; 5), low basal serum IGF-1 and good increase in growth speed at the end of the first year of treatment with recovery of final height at the end of GH therapy. Presentation: 6/3/2024

Germline Variants Of The MMR/EPCAM Genes In Russian Patients With Lynch Syndrome

Objective — Lynch syndrome is the most common hereditary cancer syndrome caused by pathogenic variants in the MMR/EPCAM genes. Our goal was to study the germline variants of these genes in the largest sample of patients with Lynch syndrome in Russia. Methods — The study included data on pathogenic and likely pathogenic variants in the MMR/EPCAM genes collected from the local Registry of Hereditary Colorectal Cancer of Ryzhikh National Medical Research Centre for Coloproctology (RNMRCC). We analyzed all available data on 141 probands with Lynch syndrome: 78 men and 63 women aged 21 to 80 years treated at RNMRCC from 2012 through 2023. Results — The numbers of pathogenic and likely pathogenic variants detected in the key genes were as follows MLH1 (69 probands), MSH2 (57), MSH6 (10), EPCAM (3), PMS2 (1), and PMS1 (1). Of the 141 germline variants, 17 (12.1%) were detected for the first time: MLH1 (8 probands) MSH2 (8), and MSH6 (1). Thirteen (9.2%) of the detected variants were associated with large deletions/duplications. The most frequent pathogenic variants in the MLH1 gene were c.1852_1854del (9 probands), c.350C&gt;T (4), and c.1459C&gt;T (3). The most frequent pathogenic variants in the MSH2 gene were c.942+3A&gt;T (9 probands) and c.1288A&gt;T (3). Conclusion — Our results allowed establishing the frequency and spectrum of different types of germline variants in the MMR/EPCAM genes, which helped optimize the algorithm for selecting and diagnosing Russian patients with Lynch syndrome.

Molecular Study of the Fukutin-Related Protein (FKRP) Gene in Patients from Southern Italy with Duchenne/Becker-like Phenotype.

Pathogenic variants localized in the gene coding for the Fukutin-Related Protein (FKRP) are responsible for Limb-Girdle Muscular Dystrophy type 9 (LGMDR9), Congenital Muscular Dystrophies type 1C (MDC1C), Walker-Warburg Syndrome (WWS), and Muscle-Eye-Brain diseases (MEBs). LGMDR9 is the fourth most common hereditary Limb Girdle Muscular Dystrophy in Italy. LGMDR9 patients with severe disease show an overlapping Duchenne/Becker phenotype and may have secondary dystrophin reduction on muscle biopsy. We conducted a molecular analysis of the FKRP gene by direct sequencing in 153 patients from Southern Italy (Calabria) with Duchenne/Becker-like phenotypes without confirmed genetic diagnosis. Mutational screening of the patients (112 men and 41 women, aged between 5 and 84 years), revealed pathogenic variants in 16 subjects. The most frequent variants identified were c.427C > A, p.R143S, and c.826C > A, p.L276I (NM_024301.5). The results obtained show that the Duchenne/Becker-like phenotype is frequently determined by mutations in the FKRP gene in our cohort and highlight the importance of considering LGMDR9 in the differential diagnosis of dystrophinopathies in Calabria. Finally, this study, which, to our knowledge, is the first conducted on Calabrian subjects, will contribute to the rapid identification and management of LGMDR9 patients.

Insights from a Wolfram syndrome cohort: clinical and molecular findings from a specialized diabetes reference center.

Considering the rarity and clinical and molecular diversity of Wolfram syndrome (WS), the objective of this study was to identify patients with a clinical presentation suggestive of WS following up at a single Brazilian diabetes service and analyze their clinical and molecular characteristics. The study included all patients with a clinical presentation of WS following up between 1991 and 2022 with early-onset diabetes mellitus and other WS signs and symptoms. A retrospective analysis was conducted, including patients' age, sex, consanguinity, age at symptom onset, diagnosis of diabetes mellitus, optic atrophy, diabetes insipidus, neurological and psychiatric disorders, hearing loss, urinary disorders, hypogonadism, and WFS1 molecular analysis. Eight patients were identified, all of whom were diagnosed with diabetes mellitus at an average age of 3.7 years. Optic atrophy, diabetes insipidus, and hearing loss were common, while psychiatric and neurological alterations were observed in some cases. Genetic analysis revealed pathogenic variants in homozygosity or compound heterozygosity. The most frequent variant was p. Val412Serfs29, present in five of the seven families. This study represents the second-largest Brazilian sample of WS and is the first cohort from a single center in Southeast Brazil. The patients had an early, severe, and complete clinical presentation. The genetic variants identified were consistent with previous literature descriptions. The variant p. Val412Serfs29 was particularly common in this cohort, highlighting its relevance in the region.

Abstract A011: PVT1 risk variant rs127920247 for colorectal cancer is shared by African American and Hispanic colorectal cancer patients

Abstract Background: Colorectal cancer, one of the most lethal and prevalent cancers across the world, is in large part due to genetic mutations. The plasmacytoma variant translocation 1 (PVT1) gene has an established association with many cancers, including colorectal cancer. There is increasingly abundant data on the mechanisms of action of PVT1 leading to the initiation and progression of these cancers. Identifying PVT1 variants linked to cancer may lead to uncovering their utility as diagnostic or prognostic biomarkers. The All of Us Research hub contains a diverse set of data from hundreds of thousands of participants. Stratifying and comparing risk variants across racial and ethnic demographics may provide insight into disparities underlying disparate incidence of colorectal cancer amongst minoritized and medically underserved communities. The All of Us database provides a novel opportunity to study PVT1 variation in a large cohort of patients from racial backgrounds with demonstrated greater incidence, prevalence, and worse outcomes from colorectal cancer. Methods: We conducted a retrospective cohort study of patients in the All of Us Research hub. The cohort studied comprised 930 patients ranging in age from 18 to 70 years with colorectal cancer, and no additional cancer diagnosis noted. Racial and ethnic backgrounds were selected if there were at least 100 patients of identified background with colorectal cancer. These consisted of patients of: African American, non-Hispanic white, and Hispanic backgrounds. We extracted data from short-read whole genome sequencing. A filtered matrix was built comparing the genetic sequence of our cohort of cancer patients to the reference genome GRCh38. We then stratified the different variants by allelic frequency across the sample cohort to report the variants with the greatest frequencies. All analyses were conducted using Python on Jupyter Notebook in the All of Us Research platform. Results: The top 5 PVT1 variants with the greatest frequency in patients of the three chosen racial and ethnic backgrounds were identified and compared to find commonalities. Rs127920247 was a PVT1 risk variant shared by African American and Hispanic patients as the 2nd highest risk variant for both. The most frequent risk variants for each group is as follows: Rs128085054 for African Americans, Rs128139524 for Non-Hispanic White Americans, and Rs127870242 for Hispanic Americans. Conclusion: PVT1 risk variants in colorectal cancer can be uncovered from data in the All of Us Research hub. Thus, genetic risk variants for cancers can be uncovered from analysis of data available in the All of Us Research hub. Identification of specific PVT1 variants similarly prevalent in colorectal cancer amongst distinct racial and ethnic communities is a significant first step towards developing them as potential diagnostic or prognostic tools. Citation Format: Sujay Singh, Olorunseun Ogunwobi. PVT1 risk variant rs127920247 for colorectal cancer is shared by African American and Hispanic colorectal cancer patients [abstract]. In: Proceedings of the 17th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2024 Sep 21-24; Los Angeles, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2024;33(9 Suppl):Abstract nr A011.

Phenotypic and genetic characterization of children with Wilson Disease from Northeast China

BackgroundWilson disease (WD) is an autosomal recessive inherited disease caused by ATP7B variants and characterized by copper metabolism defects. However, children with WD are often asymptomatic, making the clinical diagnosis difficult. Therefore, more accurate methods are required for clinical diagnosis. The objective of this study was to highlight the phenotypic and genetic characteristics of children with WD in northeast China.MethodsWe retrospectively analyzed the clinical data and gene sequencing results of 65 children with WD from January 1, 2014, to December 31, 2022, at the Shengjing Hospital of China Medical University. All data refer to the time of diagnosis before treatment.ResultsThe median age at diagnosis was 5 years (range 1.2–15 years). In 50 cases (50/65, 76.9%) patients, routine physical examinations revealed only abnormal liver function. However, they had a significantly negative (p < 0.05) Kayser–Fleischer ring (KF). Children with acute liver failure had significantly increased 24 h urinary copper excretion (p < 0.05). We detected 46 genetic variants of ATP7B, including seven novel variants. The most frequent variant was p.R778L with an allele frequency of 38.7%. Phenotype-genotype correlation analysis suggested that p.R778L was significantly associated with lower serum ceruloplasmin levels and higher zinc levels (p < 0.05). The loss-of-function (LOF) variant was associated with significantly lower albumin levels (p < 0.05).ConclusionMost children with WD are asymptomatic, which makes early diagnosis of WD difficult. Therefore, clinical and laboratory characteristics as well as genetic testing are essential. p.R778L is the most frequent variant of ATP7B in China and may play an important role in lowering serum ceruloplasmin levels.

Frequent genetic variants of autosomal recessive non-syndromic forms of inherited retinal diseases in the Russian Federation

Frequent genetic variants of autosomal recessive non-syndromic forms of inherited retinal diseases in the Russian Federation

Molecular investigation of MEFV gene polymorphisms among patients with familial mediterranean fever-like symptoms.

The diagnosis of familial Mediterranean fever (FMF) is primarily based on clinical standards. The purpose of this study was to investigate the relevance of Mediterranean fever (MEFV) genetic testing in the diagnosis of FMF as well as to identify the most frequent variant alleles and their relationship to clinical symptoms in Egyptian patients. Egyptian patients with a clinical suspicion of having FMF were studied in order to determine MEFV genotypes. Each patient was meticulously evaluated through an extensive collection of their medical history, a thorough clinical examination, and a series of laboratory tests, encompassing CBC, ESR, and CRP measurements. The MEFV variant screening procedure included the use of reverse dot blot hybridization. The average age of our patients when they were given a diagnosis was 22.8 ±1.404 years old. The predominant clinical manifestations identified were abdominal pain, fever, and arthralgia. Molecular interrogation of the MEFV gene unveiled that a significant proportion of the cohort, constituting 72 individuals (60%), displayed heterozygosity, whereas a smaller fraction, comprising 12 subjects (10%), demonstrated homozygosity and an equivalent number (10%) exhibited compound heterozygosity. Pertaining to the distribution of allele variants, E148Q emerged as the most prevalent, succeeded by M694I, accounting for 12.5% of the cases, and M680I (G/A), representing 10.41%. This notable prevalence of heterozygous genotypes among the Egyptian demographic, preliminarily identified as potential FMF cases, underscores the imperative for molecular diagnostics to enhance the precision of FMF identification.

C9orf72 gene repeat expansion phenotype profile of motor neurone disease in Portugal

BackgroundC9orf72 gene repeat expansion (C9RE) is the most frequent gene variant associated with amyotrophic lateral sclerosis (ALS). We aimed to study the phenotype of motor neurone disease (MND) patients with C9RE in a Portuguese cohort. MethodsDemographical and clinical data of MND patients with (C9RE+) and without C9RE were compared. ALS al Rating Scale-Revised (ALSFRS-R) and Edinburgh Cognitive and Behavioural ALS Screen (ECAS) were used to evaluate functional and cognitive performance, respectively. Survival analysis was performed using Kaplan Meier log-rank test and Cox proportional hazards model. ResultsWe included 761 patients of whom 61 (8.0 %) were C9RE+. C9RE+ patients had a higher frequency of ALS (95.1 vs 78.4 %, p = 0.002), and lower frequency of progressive muscular atrophy (3.3 vs 16.7 %, p = 0.006). C9RE+ was associated with earlier age of onset (58.1 vs 62.6 years, p = 0.003) and more frequent MND family history (65.5 vs 11.4 %, p < 0.001). Gender, ethnicity, onset site, diagnostic delay, disease progression rate until diagnosis (ΔF), ALSFRS-R and time until non-invasive ventilation did not differ between groups. Cognitive/behavioural symptoms and ECAS did not differ between groups, except a worse visuospatial score in C9RE+ group (p = 0.035). Death rate was 1.8 and 1.6 times higher in C9RE+ patients with MND and ALS, respectively. Significant survival prognostic factors in C9RE+ group were diagnosis delay (HR = 0.96, 95 %CI 0.92–0.99, p = 0.008) and ΔF (HR = 1.93, 95 %CI 1.26–2.96, p = 0.002). ConclusionOur study corroborates most previous cohorts' findings, but harbours some singularities regarding onset site, phenotype, and cognitive profile, that contribute to a better understanding of C9RE epidemiology.

Prevalence of internal iliac artery anatomical variants in a Mexican population

The internal iliac artery arises as a terminal extension of the common iliac artery and supplies blood to the pelvic region. This study aims to identify the anatomic variations of the internal iliac artery (IIA) in a Mexican population sample. This is a retrospective cross-sectional observational study. A total of 81 angiographies via the femoral artery approach performed on patients undergoing various medical procedures were included. Variations in the IIA branching patterns were identified by evaluating the angiographic images and grouped according to Adachi’s classification into five types (I–V). A total of 139 hemipelvises were analyzed (78 right and 61 left). The frequencies of each type of variation were as follows: Type I (71.2%), Type II (10.79%), Type III (0 cases), Type IV (0.7%), Type V (12.94%), and unclassified (4.31%). The most frequent anatomical variants of the IIA in the western Mexican population sample were Type I, followed by Types V and II. Even though Type V is rare in most populations, it was the second most frequent variant in this study. Understanding the variants of the IIA branching pattern is necessary for performing invasive procedures in the pelvic region with precision and minimizing complications.

Uncovering structural variants in Creole cattle from Guadeloupe and their impact on environmental adaptation through whole genome sequencing.

Structural variants play an important role in evolutionary processes. Besides, they constitute a large source of inter individual genetic variation that might represent a major factor in the aetiology of complex, multifactorial traits. Their importance in adaptation is becoming increasingly evident in literature. Yet, the characterization of the genomic landscape of structural variants in local breeds remains scarce to date. Herein, we investigate patterns and gene annotation of structural variants in the Creole cattle from Guadeloupe breed using whole genome sequences from 23 bulls representative of the population. In total, we detected 32821 ascertained SV defining 15258 regions, representing ~ 17% of the Creole cattle genome. Among these, 6639 regions have not been previously reported in the Database of Genomic Variants archive. Average number of structural variants detected per individual in the studied population is in the same order of magnitude of that observed in indicine populations and higher than that reported in taurine breeds. We observe an important within-individual variability where approximately half of the detected structural variants have low frequency (MAF < 0.25). Most of the detected structural variants (55%) occurred in intergenic regions. Genic structural variants overlapped with 7793 genes and the predicted effect of most of them is ranked as "modifier". Among the structural variants that were predicted to have a high functional impact on the protein, a 5.5 Kb in length, highly frequent deletion on chromosome 2, affects ALPI, a gene associated with the interaction between gut microbiota and host immune system. The 6639 newly identified structural variants regions include three deletions and three duplications shared by more than 80% of individuals that are significantly enriched for genes related to tRNA threonylcarbamoyladenosine metabolic process, important for temperature adaptation in thermophilic organisms, therefore suggesting a potential role in the thermotolerance of Creole cattle from Guadeloupe cattle to tropical climate. Overall, highly frequent structural variants that are specific to the Creole cattle population encompass olfactory receptor and immunity genes as well as genes involved in muscle tone, muscle development and contraction. Beyond mapping and characterizing structural variants in the Creole cattle from Guadeloupe breed, this study provides valuable information for a better understanding of the potential role of chromosomal rearrangements in adaptive traits in cattle.