Genetic Counseling Of Families Research Articles

Familial adenomatous polyposis: a case report

BackgroundFamilial adenomatous polyposis is characterized by the presence of multiple colorectal adenomatous polyps and caused by germline mutations in the tumor suppressor gene and adenomatous polyposis coli, located on chromosome 5q21–q22. Familial adenomatous polyposis occurs in approximately 1/10,000 to 1/30,000 live births, and accounts for less than 1% of all colorectal cancers in the USA. It affects both sexes equally and has a worldwide distribution. The incidence of colon cancer in low- and middle-income countries is rising. In addition to the increasing incidence, lack of early detection and impeded access to optimal multidisciplinary treatment may worsen survival outcomes. Developing quality diagnostic services in the proper health context is crucial for early diagnosis and successful therapy of patients with colorectal cancer, and applying a resource-sensitive approach to prioritize essential treatments on the basis of effectiveness and cost-effectiveness is key to overcoming barriers in low- and middle-income countries. We report a case of familial adenomatous polyposis presenting as adenocarcinoma with multiple colorectal adenomatous polyps. The diagnosis of familial adenomatous polyposis was made by the presence of numerous colorectal adenomatous polyps and family history of colonic adenocarcinoma. Due to its rarity, we decided to report it.Case presentationA 22-year-old Ethiopian female patient presented to Addis Ababa University College of Health science, Addis Ababa, Ethiopia with rectal bleeding. Abdominopelvic computed tomography scan was done and showed distal rectal asymmetric anterior wall thickening in keeping with rectal tumor. Colonoscopy was done and she was diagnosed to have familial adenomatous polyposis with severe dysplasia. In the meantime, colonoscopy guided biopsy was taken and the diagnosis of adenocarcinoma with familial adenomatous polyposis was rendered. For this, total proctocolectomy was carried out. On laparotomy there was also incidental finding of left ovarian deposition for which left salpingo-oophorectomy was done, and 4 weeks after surgical resection, the patient was started on oxaliplatin, leucovorin, fluorouracil chemotherapy regimen.ConclusionIn the clinical evaluation of a patient with rectal bleeding, familial adenomatous polyposis must be considered as a differential diagnosis in subjects having family history of colonic adenocarcinoma for early diagnostic workup, management, family genetic counseling, and testing.

A novel variant (p.A524P) in Spastin is responsible for a Chinese family with hereditary spastic paraplegia.

Hereditary spastic paraplegia (HSP) represents a group of monogenic neurodegenerative disorders characterized by high clinical and genetic heterogeneity. HSP is characterized by slowly progressing hypertonia of both lower extremities, spastic gait, and myasthenia. The most prevalent autosomal dominant form of HSP, known as spastic paraplegia 4 (SPG4), is attributed to variants in the spastin (SPAST) gene. Here, a Chinese family presenting with spasticity in both legs and a shuffling gait participated in our investigation. Whole exome sequencing of the proband was utilized to identify the genetic lesion in the family. Through data filtering, Sanger sequencing validation, and co-separation analysis, a novel variant (NM_014946.3: c.1669G > C:p.A557P) of SPAST was identified as the genetic lesion of this family. Furthermore, bioinformatic analysis revealed that this variant was deleterious and located in a highly evolutionarily conserved site. Our study confirmed the diagnosis of SPG4 in this family, contributing to genetic counseling for families affected by SPG4. Additionally, our study broadened the spectrum of SPAST variants and highlighted the importance of ATPases associated with various cellular activity domains of SPAST.

Molecular diagnosis of Alpha-sarcoglycanopathies by NGS in seven Moroccan families and report of two novel variants.

Limb-girdle muscular dystrophies constitute a heterogeneous group of neuromuscular diseases, both clinically and genetically. Limb-girdle muscular dystrophy by alpha-sarcoglycan deficiency or LGMD R3 α-sarcoglycan-related is a subtype of the autosomal recessive sarcoglycanopathies caused by variants in the alpha-sarcoglycan gene (SGCA) at 17q21.33. It appears in childhood by progressive weakness of pelvic and/or scapular girdle muscles and calf hypertrophy, with a wide range of clinical inter- and intra-familial clinical variability. Our report extends the molecular spectrum of SGCA gene with the identification of variant disease causing and will help for better management of patients and genetic counseling of families. In our study, seven unrelated families presented a clinical and paraclinical picture consistent with alpha-sarcoglycanopathy. A molecular study using Next-Generation Sequencing (NGS) was carried out on them. Six different homozygous variants of the SGCA gene were identified in the patients analyzed, including four previously reported variants and two novel variants predicted to be deleterious by the prediction tools. Our results expand the spectrum of variants in Moroccan patients with sarcoglycanopathy, specifically LGMDR3, most importantly as this form is not common in the Moroccan population.

Clinical characteristics and genetic analysis of a case of a patient with familial hereditary breast cancer: a case report

BackgroundBreast cancer has emerged as the foremost cause of female mortality worldwide, with triple negative breast cancer accounting for approximately 10–15% of all breast cancer cases. The triple negative breast cancer family has obvious familial heritability, but no potential pathogenic variation was found in BRCA1/2.Case presentationThe patient was a 56-year-old woman of Han ethnicity. The clinical characteristics of this patient with breast cancer were summarized, peripheral blood of one normal female and two patients with breast cancer in this family was collected, DNA was extracted, and the potential pathogenic variation was analyzed by whole exome sequencing. The normal female and two patients with breast cancer in this family shared a maternal grandmother. The proband’s right breast mass was punctured, and the biopsy showed invasive carcinoma of the right breast, grade II–III, with necrosis. No mutation was found in BRCA1/2 gene test; immunohistochemical of surgical specimens showed triple negative breast cancer. Three mutation types and 17 gene mutation sites were detected through bioinformatics prediction analysis on the basis of co-segregation of genotype and phenotype within the family and whole exome sequencing results. Combined with the Cancer Genome Atlas database comprehensive analysis, the MT1E c.G107A (p.C36Y) mutation may be a potential pathogenic site.ConclusionsThrough whole exome sequencing, we identified a total of 17 potential pathogenic mutation loci, none of which have been reported thus far. Therefore, our work expanded the gene mutation spectrum of familial hereditary triple negative breast cancer, which can provide more basis for family genetic counseling.

Exome sequencing revealed variants in SGCA and SIL1 genes underlying limb girdle muscular dystrophy and Marinesco-Sjögren syndrome patients.

Inherited neuromuscular (NMD) and neurodegenerative diseases (NDD) belong to two distinct categories that disturb different components of the nervous system, leading to a variety of different symptoms and clinical manifestations. Both NMD and NDD are a heterogeneous group of genetic conditions. Genetic variations in the SGCA and SIL1 genes have been implicated in causing Limb Girdle Muscular Dystrophy (LGMD), a type of neuromuscular disorder, and Marinesco-Sjögren Syndrome (MSS) which is a neurodegenerative disorder. In the present study, we have investigated four patients presenting LGMD and five patients with MSS features. After collecting detailed clinical and family history, necessary laboratory investigations, including estimation of a skeletal muscle marker enzyme serum creatine kinase (CK), nerve conduction study (NCS), electromyography (EMG), echocardiography (Echo), Magnetic resonance imaging (MRI -brain), CT-brain and X-rays were performed. Whole exome followed by Sanger sequencing was employed to search for the disease-causing variants. Physical examination in LGMD patients revealed poor muscle tone and facing difficulty in straightening up from the floor. Clinical history revealed frequent falls and strenuousness in climbing stairs. They started toe-walking in early childhood. Laboratory investigations confirmed elevated CK levels and abnormal NCS and EMG. The MSS patients showed abnormalities in gate and jerking movement, abnormal speech, and strabismus with cataract. MRI-brain showed cerebral atrophy in some MSS patients with elevated CK levels. Whole exome sequencing revealed a nonsense variant [c.C574T, p.(Arg192*)] in the SGCA gene and a frameshift [c.936dupG, p.(Leu313AlaFs*39)] in the SIL1 gene in LGMD and MSS patients, respectively. Our study emphasizes the significance of integrating clinical and genetic analyses for precise diagnosis and tailored management strategies in inherited NMD and NDD disorders. To the best of our knowledge, this is the first study documenting SGCA and SIL1 recurrent variants in subcontinent populations with few rare clinical features. The recurrent mutations expanding the global understanding of the mutation's geographic and ethnic distribution and contributing valuable epidemiological data. The study will facilitate genetic counseling for families experiencing similar clinical features, both within Pakistani populations and in other regions.

Clinical and genetic analysis of Niemann-Pick disease type C with a novel NPC1 variant

BackgroundNiemann-Pick disease type C poses a significant challenge within the landscape of rare genetic disorders, marked by its connection to variants in the NPC1 or NPC2 genes. This autosomal recessive lipid storage disorder unfolds with a relentless progression of neurological deterioration and a distinctive hallmark of hepatosplenomegaly.Case presentationThis case report delves into the intricate presentation of a 9-year-old Iraqi boy exhibiting heightened walking instability and speech slurring. His medical history unfolds a series of challenges, including neonatal hyperbilirubinemia, hepatosplenomegaly, and recurrent nasal bleeding. A comprehensive physical examination reveals motor and neurological abnormalities such as an inability to squat and rise, vertical gaze palsy, and dysdiadochokinesia. Further investigations, encompassing laboratory tests and imaging studies, coupled with the identification of foamy cells in bone marrow smears, raise significant concerns about Niemann-Pick disease type C. By utilizing whole exome sequencing, we pinpointed a previously unreported homozygous variant—c.2925_2928delCTGC; p.Cys976PhefsTer6—found within exon 20 (NM_000271.5) of the proband’s NPC1 gene.ConclusionsThis study significantly advances our understanding of the c.2925_2928del (C976Ffs*6) variant in the NPC1 gene, shedding light on the complexities of Niemann-Pick disease type C. Beyond its scientific significance, the findings provide crucial insights for familial genetic counseling and prenatal diagnoses. This research expands our knowledge of the variant’s genetic landscape, making it a valuable resource in both academic and clinical settings, particularly for families dealing with Niemann-Pick disease type C.

P-508 Management of incidental findings after preconception expanded carrier screening: identifying genetic predispositions to cancer and metabolic conditions in 8010 screened ART patients

Abstract Study question How do individuals and fertility clinics navigate incidental findings from Expanded Carrier Screening (ECS) in reproductive decision-making? Summary answer Incidental ECS findings prompted varied responses from patients and gamete donors, influencing diverse reproductive choices and underscoring the pivotal role of pre-test genetic counseling. What is known already ECS aims to assess reproductive risk in the general population for specific autosomal recessive and X-linked conditions. These manifest in infancy or early childhood and impact life expectancy or the quality of life. ECS results may guide interventions to avoid affected pregnancies, such as the implementation of preimplantation genetic testing of embryos (PGT-M). Additionally, ECS has the potential to uncover incidental findings with significant health implications, such as an elevated cancer risk or diagnosis. However, the lack of comprehensive reporting guidelines necessitates meticulous analysis to ensure effective clinical guidance for these individual findings. Study design, size, duration This retrospective descriptive study assessed the results of ECS tests performed in 5475 patients and 2535 oocyte and semen donors from four different fertility clinics between July 2017 and December 2023. ECS reports with incidental findings in the ATM, FH or LDLR genes were identified and further examined. We calculated individual and reproductive risks for affected individuals and recorded the subsequent clinical management pertaining to each case. Participants/materials, setting, methods Pre-test counselling was offered to both patients and gamete donors before consenting to ECS. Testing was outsourced to an external genetics laboratory using a panel of 309 genes analyzed through next generation sequencing and complementary molecular techniques. The laboratory reported pathogenic and likely pathogenic variants that were subsequently manually reviewed by an internal genetics committee. Personal and reproductive risks were assessed for each case and genetic counseling was provided in a subsequent meeting. Main results and the role of chance Genetic variants in ATM, FH, or LDLR genes were reported in 134 out of 8010 individuals undergoing ECS (1.67%). Among these, 108 variants were identified in patients: 53.7% (n = 58) in ATM, 19.4% in FH (n = 21), and 26.8% (n = 29) in LDLR. Out of the variants identified as incidental findings, 20/108 were actionable and eligible for PGT-M: 19 were associated with an increased risk for breast cancer and 1 for renal cancer. After being informed of the findings and their implications, 7/20 couples opted to revoke treatment as, according to internal policies, PGT-M was mandatory in such cases; 6/20 couples chose to undergo double gamete donation; 6/20 couples opted for PGT-M. Patients with pathogenic variants in LDLR linked to autosomal dominant inheritance for familial hypercholesterolemia (20/108, 18.5%), received follow-up guidelines and family genetic counseling. Pathogenic variants in ATM, FH, and LDLR were also identified in 26 gamete donors (24 oocyte donors and 2 sperm donors). Following internal review, 14 of these variants were considered incidental findings with an increased risk for breast cancer (13/14) or familial hypercholesterolemia (1/14), leading to the exclusion of these potential donors from the donation program. Limitations, reasons for caution The reproductive handling of incidental findings in our population relies on subjective decisions by the internal genetics committee, which may evolve with scientific advancements and recommendations from professional societies. Follow-up data on long-term reproductive outcomes are lacking. Wider implications of the findings This study reveals the diverse reproductive decisions made in response to incidental findings, underscoring the importance of pre-test genetic counseling. Our findings also highlight the subsequent impact on fertility programs, which may lead to the exclusion of gamete donors or patients choosing to revoke treatment. Trial registration number Not Applicable

Novel pathogenic variants in HR underlie atrichia with papular lesions in a cohort of 10 families.

Atrichia with papular lesions (APL) is a hair abnormality characterized by loss of hair on the scalp and rest of the body. In a few cases, hair loss is accompanied by the appearance of keratotic papules on the body. It is inherited in an autosomal recessive manner. Sequence variants in the HR (hairless) gene are responsible for this hair abnormality. Here, we present nine consanguineous families and one nonconsanguineous family with clinical manifestations of APL. Whole exome followed by Sanger sequencing and/or direct Sanger sequencing was performed to identify pathogenic variants. The study revealed seven novel pathogenic variants c.794del;p.(Pro265Argfs*98), c.2921-2936del;p.(Tyr974Leufs*16), c.2889C>A;p.(Cys963*), c.2689C>T;p.(Gln897*), c.3186_3187dup;p.(Gln1063Profs*43), c.560dup;p.(Tyr188Ilefs*131), c.2203+5G>C, c.2776+5G>A, and the previously reported variant c.1837C>T;p.(Arg613*) in HR in these families. The study not only expands the mutational spectrum in the HR gene but also highlights the unusual phenotypic findings and will facilitate genetic counseling of families with members showing various types of hair loss disorders in the local population.

NR3C2 microdeletions-an underrecognized cause of pseudohypoaldosteronism type 1A: a case report and literature review.

Pseudohypoaldosteronism type 1A (PHA1A) is caused by haploinsufficiency of the mineralocorticoid receptor (MR). Heterozygous small insertions/deletions, transitions, and/or transversions within NR3C2 comprise the majority (85%-90%) of pathogenic copy number variants. Structural chromosomal abnormalities, contiguous gene deletion syndromes, and microdeletions are infrequent. We describe a neonate with PHA1A due to a novel NR3C2 microdeletion involving exons 1-2. Literature review identified 39 individuals with PHA1A due to NR3C2 microdeletions. Transmission modality, variant description(s), testing method(s), exon(s) deleted, and affected functional domain(s) were characterized. In total, 40 individuals with NR3C2 microdeletions were described: 19 involved contiguous exons encoding a single MR domain; 21 involved contiguous exons encoding multiple MR domains. Transmission modality frequency was familial (65%), de novo (20%), or unknown (15%). Sequencing (Sanger or short-read next-generation) failed to detect microdeletions in 100% of tested individuals (n = 38). All were detected using deletion/duplication testing modalities. In 2 individuals, only microarray-based testing was performed; microdeletions were detected in both cases. Initial testing for PHA1A should rely on sequencing to detect the most common genetic alterations. Deletion/duplication analysis should be performed when initial testing is nondiagnostic. Most NR3C2 microdeletions are parentally transmitted, thus highlighting the importance of familial genetic testing and counseling.

Clinical and Molecular Characteristics of Neuronal Ceroid Lipofuscinosis in Saudi Arabia

BackgroundNeuronal ceroid lipofuscinoses (NCLs) represent a heterogeneous group of inherited metabolic lysosomal disorders characterized by neurodegeneration. This study sought to describe the clinical and molecular characteristics of NCLs in Saudi Arabia and determine the most common types in that population. MethodsA retrospective review of electronic medical records was conducted for 63 patients with NCL (55 families) from six tertiary and referral centers in Saudi Arabia between 2008 and 2022. Clinical, radiological, and neurophysiological data as well as genetic diagnoses were reviewed. ResultsCLN6 was the predominant type, accounting for 45% of cases in 25 families. The most common initial symptoms were speech delay (53%), cognitive decline (50%) and/or gait abnormalities (48%), and seizure (40%). Behavioral symptomatology was observed in 20%, whereas visual impairment was less frequently (9.3%) encountered. Diffuse cerebral and cerebellar atrophy was the predominant finding on brain magnetic resonance imaging. Electroencephalography generally revealed background slowing in all patients with generalized epileptiform discharges in 60%. The most common genotype detected was the p.Ser265del variant found in 36% (20 of 55 families). The most rapidly progressive subtypes were CLN2 and CLN6. Two patients with each died at age five years. The earliest age at which a patient was nonambulatory was two years in a patient with CLN14. ConclusionsThis is the largest molecularly confirmed NCL cohort study from Saudi Arabia. Characterizing the natural history of specific NLC types can increase understanding of the underlying pathophysiology and distinctive genotype-phenotype characteristics, facilitating early diagnosis and treatment initiation as well as genetic counseling for families.

Prevalence of variant of unknown significance (VUS) in men with prostate cancer who serve as a benchmark for enhanced screening and for personalized therapy.

342 Background: Pathogenic variants (PVs) in DNA repair genes (DRG), such as in BRCA1, BRCA2, ATM, CHEK2, etc., have implications for prostate cancer (PCa) family genetic counselling, testing and risk stratification in men. However, understanding how to counsel patients with variants of unknown significance (VUS) is an unmet clinical need. On the other hand, there is the necessity to cautiously interpret VUS findings and to bolster VUS evaluations with additional evidence for pathogenicity. In this study, we aim to investigate the prevalence of germline VUS in men with PCa and their association with outcomes after robot-assisted radical prostatectomy (RARP). Methods: This is a nested cohort case study from an ongoing PCa screening, set to identify and screen men in the Italian population with a genetic predisposition (AIRC - Fondazione AIRC per la Ricerca sul Cancro project IG 2020 ID 25027). Cases for the current analysis were selected by “Adam's rib strategy” searching for germline DRG variant in men with a diagnosis of high-risk PCa who were scheduled for RARP. After informed consent was signed, a blood sample was obtained. A previously validated multigene panel test was used to assess the presence of germline variants. PVs and VUS were classified according to the American College of Medical Genetics and Genomics and Association for Molecular Pathology consensus criteria and International Agency for Research on Cancer guidelines. The primary endpoint was to describe the prevalence of VUS and the secondary to correlate VUS with pathological outcomes after RARP. Results: A total of 118 men with diagnosis of PCa who underwent RP were enrolled. The mean age at diagnosis of PCa was 65.9 (±6.42) years; pathological grade was ISUP 1-2 in 58.0% patients and 3-5 in 42.0%. Of the 76 men evaluated, 18 (23.7%) had a VUS and 1 (1.32%) a pathogenic germline variant in BRCA1 and PALB2. Among those with VUS younger men at diagnosis were more likely to carry a VUS than older at diagnosis mean (age 64 ± 6.41 vs. 66 ± 7.20 years). Additionally, 33.3% vs 16.2 % were carrier of VUS and N+ and required adjuvant androgen deprivation therapy. No difference between ISUP at final pathology and positive margin rate were found. Conclusions: Our findings showed a high prevalence of VUS germline mutations in PCa patients undergoing RARP. These mutations seem to be associated with worse pathological outcomes. Limitations includes short follow-up and absence of non-Caucasian patients.

Novel compound heterozygous mutations of the NPC1 gene associated with Niemann-pick disease type C: a case report and review of the literature

BackgroundNiemann-Pick Disease type C is a fatal autosomal recessive lipid storage disorder caused by NPC1 or NPC2 gene mutations and characterized by progressive, disabling neurological deterioration and hepatosplenomegaly. Herein, we identified a novel compound heterozygous mutations of the NPC1 gene in a Chinese pedigree.Case presentationThis paper describes an 11-year-old boy with aggravated walking instability and slurring of speech who presented as Niemann-Pick Disease type C. He had the maternally inherited c.3452 C > T (p. Ala1151Val) mutation and the paternally inherited c.3557G > A (p. Arg1186His) mutation using next-generation sequencing. The c.3452 C > T (p. Ala1151Val) mutation has not previously been reported.ConclusionsThis study predicted that the c.3452 C > T (p. Ala1151Val) mutation is pathogenic. This data enriches the NPC1 gene variation spectrum and provides a basis for familial genetic counseling and prenatal diagnosis.

P-42 A delayed diagnosis of MEN1 syndrome

Abstract Introduction Multiple endocrine neoplasia 1 (MEN 1) is a rare autosomal dominantly inherited syndrome that results from mutations in the MEN1 gene. It is characterized by multiple tumors of endocrine glands and some other tissues. Early diagnosis is crucial for optimal management. Here we present a patient with delayed diagnosis and preventable metastatic disease. Clinical Case A 46-year-old male patient who was referred from gastroenterology clinic to our outpatient clinic following distal pancreatectomy. The postoperative pathology was reported as a well-differentiated neuroendocrine tumor (NET) with 3 focuses (60 mm, 9 mm and 2.5 mm in size). Six months ago, he underwent to Magnetic Resonance Imagination (MRI) of the abdomen because of abdominal pain and 17 kg weight loss in a year, that revealed a 69×67 mm cystic lesion in the tail of the pancreas (Figure 1A). Laboratory and physical examinations were in accordance with a nonfunctioning lesion (Table 1). The findings of the Gallium-68 DOTATATE PET/CT suggested residual and metastatic disease during follow-up (At the level of the pancreatic corpus, increased uptake was detected in two lesion sites adjacent to liver segment 3 and in various nodular lesion areas, the largest of which was approximately 20 mm in diameter, adjacent to the duodenum and pancreas (Figure 1B and 1D). No increased uptake was observed in the pancreas and these lesions in preoperative FDG/PET (Figure is not shown). The patient was consultated by oncology clinic and 177-Lutetium-DOTATATE and octreotide treatments were started. Parathyroidectomy and total thyroidectomy 7 years ago was noted in the patient's medical history. Persisting hypercalcemia and elevated PTH were also remarkable in laboratory testing (Table 2). The patient didn't apply to endocrinology clinic after parathyroidectomy and hypercalcemia had been overlooked for 7 years. Further investigation revealed a nonfunctioning 4 mm diameter pituitary lesion (Figure 1C). So the diagnosis of multiple endocrine neoplasia type 1 was suspected. Genetic test detected a c.784-2A>G spice site variant in MEN1 gene in heterozygous form. The patient denied a family history for MEN 1 but he reported that his father died at the age of 40 and his uncle at the age of 39 due to an illness of unknown origin, and two sons of the same uncle were followed up for parathyroid disease. Family screening and genetic counseling were recommended. Surgery of the remaining parathyroid glands and implantation in the forearm and thymectomy were planned. Conclusion MEN syndromes are rare and hypercalcemia is generally the initial presentation. Persistence of hypercalcemia following parathyroidectomy should be warning, and the possibility of MEN -1 syndrome should also be kept in mind even in the lack of family history. As in the presented case, diagnosis may be delayed due to late appearance of symptoms of other components, especially nonfunctional pancreaticoduodenal tumors.Figure 1.MRI and Ga-68 PET/CT images of the patientA: A 69×67 mm cystic lesion in the tail of the pancreas B: Increased Gallium-68 DOTATATE uptake at the level of the pancreatic corpus adjacent to liver segment 3 (SUVmax: 67.90) C: A nonfunctioning 4 mm diameter lesion in the right half of the pituitary D: Increased uptake of Gallium-68 DOTATATE in nodular lesions adjacent to the duodenum and pancreas (SUVmax: 31.09) Table 1.Laboratory results of the patientACTH: Adrenocorticotropic hormone, FSH: follicle stimulating hormone, LH: luteinizing hormone, IGF-1: Insülin-like growth factor, TSH: Thyroid stimulating hormone, 1 mg DST: dexamethasone suppression test Table 2.Calcium and PTH levels of the patient before parathyroidectomy and following parathyroidectomy*Before parathyroidectomy ** Following parathyroidectomy PTH: Parathyroid hormone

Angelman syndrome: A genetic challenge for physical and learning disabilities

Angelman syndrome (AS) was first reported in 1965 by Dr. Harry Angelman. It is a condition of neurodevelopment characterized by, a lack of speech, distinctive behavior, seizure, intellectual capacity, and cheerful disposition. The cause of AS is a lack of production by maternal imprinted genes (UBE3A) on the 15q11-q13 chromosome. The complications of AS are strabismus, atrophy of the optical nerve, and blindness, which are rarely reported. There is a possibility of complications in the laboratory diagnostic tests for AS. One method is to evaluate with DNA methylation analysis of AS/Prader-Willi Syndrome (PWS) imprinting center (IC). On cytogenetic analysis, at least 50–60% of patients had a maternally induced de novo mutation of chromosome 15q11-13 with more serious clinical phenotypes such as microcephaly, seizures, language impairment, and motor difficulties. Multiexonic or whole gene deletion is identified by array-comparative genomic hybridisation (CGH) in some cases and laboratory and methodology may vary such deletions. Diagnosis of AS can be suggested by unsteady movements before walking. Based on the patient’s medical history, electroencephalogram (EEG) data, clinical symptoms, and the presence or absence of a chromosome 50 deletion, a diagnosis of AS is made. Incidence estimated for AS is approximately 1 in 12,000–20,000 birth lives, but the epidemiological measures of life expectancy remains unknown. The clinical features of AS phenotype include seizures, sleep disturbance, intellectual disability, and movement disorders such as tremor and ataxia, anxiety, expressive language is limited, behavioral changes, pleasant demeanor, and easily manipulated laughs, EEG abnormalities were discovered in around 100% of the patients. The researcher identified problems with inflammation at the injection site caused by a higher dose of a drug and they monitored proteins in the individual’s blood and cerebrospinal fluid as an additional safety precaution. Genetic counseling for families with one child with AS to address the likelihood of recurrence can be a challenging subject that frequently requires specialist advice.

Hereditary conditions associated with elevated cancer risk in childhood

The widespread use of next-generation sequencing (NGS) technologies revealed that a significant percentage of tumors in children develop as a part of monogenic hereditary diseases. Predisposition to the development of pediatric neoplasms is characteristic of a wide range of conditions including hereditary tumor syndromes, primary immunodeficiencies, rasopathies, and phakomatosis. The mechanisms of tumor molecular pathogenesis are diverse and include disturbances in signaling cascades, defects in DNA repair, chromatin remodeling, and microRNA processing. Timely diagnosis of tumor-associated syndromes is important for the proper choice of cancer treatment, genetic counseling of families, and the development of surveillance programs. The review describes the spectrum of neoplasms characteristic of the most common syndromes and the molecular pathogenesis of these diseases.

Digenic CHD7 and SMCHD1 inheritance Unveils phenotypic variability in a family mainly presenting with hypogonadotropic hypogonadism

ObjectivesCHARGE syndrome is a congenital hereditary condition involving multiple systems. Patients are easily misdiagnosed with idiopathic hypogonadotropic hypogonadism (IHH) due to the overlap of clinical manifestations. An accurate clinical diagnosis remains challenging when the predominant clinical manifestation resembles hypogonadotropic hypogonadism. MethodsThis original research is conducted based on the genetic finding and analysis of clinical cases. Whole-exome sequencing (WES) and in-silico analyse were performed on two sisters to investigate the pathogenesis in this family. Homology modelling was conducted to evaluate structural changes in the variants. ResultsWES and Sanger sequencing revealed two siblings carrying a nonsense mutation (NM_017780.4: c.115C > T) in exon 2 of CHD7 inherited from a mildly affected mother and a missense mutation (NM_015295.3: c.2582T > C) in exon 20 of SMCHD1 inherited from an asymptomatic father. The nonsense mutation in CHD7 was predicted to generate nonsense-mediated decay, whereas the missense mutation in SMCHD1 decreased protein stability. ConclusionsWe identified digenic CHD7 and SMCHD1 mutations in IHH-associated diseases for the first time and verified the synergistic role of oligogenic inheritance. It was also determined that WES is an effective tool for distinguishing diseases with overlapping features and establishing a molecular diagnosis for cases with digenic or oligogenic hereditary disorders, which is beneficial for timely treatment, and family genetic counseling.

Sequence variants in different genes underlying Bardet-Biedl syndrome in four consanguineous families.

Bardet-Biedl Syndrome (BBS) is a rare (1:13,500-1-160,000) heterogeneous congenital disorder, characterized by postaxial polydactyly, obesity, hypogonadism, rod-cone dystrophy, cognitive impairment, and renal abnormalities (renal cystic dysplasia, anatomical malformation). To date about twenty-five genes have been identified to cause BBS, which accounts for about 80% of BBS diagnosis. In the current study, we have performed mutational screening of four Pakistani consanguineous families (A-D) with clinical manifestation of BBS by microsatellite-based genotyping and whole exome sequencing. Analysis of the data revealed four variants, including a novel/unique inheritance pattern of compound heterozygous variants, p.(Ser40*) and p.(Thr259Leufs*21), in MKKS gene, novel homozygous variant, p.(Gly251Val)] in BBS7 gene and two previously reported p.(Thr259Leufs*21) in MKKS and p.(Met1Lys) in BBS5 gene. The variants were found segregated with the disorder within the families. The study not only expanded mutations spectrum in the BBS genes, but this will facilitate diagnosis and genetic counselling of families carrying BBS related phenotypes in Pakistani population.

Novel PPP1R21 mutation in a family with autosomal recessive neurodevelopmental disorder: results of genomics and molecular analysis

BackgroundNeurodevelopmental diseases are a group of disorders affecting the development of the nervous system and brain function. In particular, neurodevelopmental disorder with hypotonia, facial dysmorphism, and brain abnormalities is a novel neurodevelopmental syndrome caused by biallelic PPP1R21 loss-of-function variants. This study aimed to investigate the molecular etiology of this neurodevelopmental disorder in an Iranian patient from a consanguineous marriage family.Methods and resultsAfter clinical examination and DNA sampling, whole exome sequencing was performed for the patient. The findings were confirmed and segregated via Sanger sequencing and bioinformatics approach in the patient and parents, respectively. We identified the novel loss-of-function mutation of c.1317_1318delAG p.(Asp440Tyrfs*6) in PPP1R21 gene in our patient suffering from severe developmental delays, mental retardation, facial deformities, muscle weakness, difficulty breathing and feeding, and vision impairment. Through Sanger sequencing, the homozygous and heterozygous statuses of this variant were observed in the patient and the parents, respectively. As well, the bioinformatics approach demonstrated the disease-causing effect and clinical pathogenicity of this mutation.ConclusionsSuch findings improve our knowledge of patients with neurodevelopmental phenotypes. In addition, these results can be particularly helpful for prenatal and preimplantation diagnosis and genetic counseling of families with a high risk of infantile intellectual disabilities.

It's Never Too Late for a Diagnosis.

Zellweger spectrum disorder (ZSD) (OMIM#214100) is a phenotypic continuum ranging from severe to mild presentations. ZSD is now used in all individuals with a defect in one of the 13 ZSD-PEX genes, regardless of phenotype. Diagnosis can be suggested by abnormal levels of very long-chain fatty acids, phytanic acid, pristanic acid, plasmalogens, pipecolic acid, or bile acids. However, false negatives are frequent, mostly in older patients. Definite diagnosis is established in a proband with suggestive clinical findings by identification of biallelic pathogenic variants in one of the 13 ZSD-PEX genes. A 39-year-old female patient had a global development delay since her first year of life. Never developed oral language but had sphincter control and was able to walk and laugh. At 8 years old, she had her first seizure and lost sphincter control when she was 20 years old. At 28 years old, she had an episode of status epilepticus, with severe prostration and became bedridden. She is currently mute, without capacity for communication or motor control. She has no consanguineous parents, has a 35 year old brother with global developmental delay and their mother had a history of an abortion, without other relevant family history. Brain MRI of the patient revealed severe leukodystrophy mainly periventricular, bilateral and symmetric, and less prominent in the cerebellar white matter, with severe cerebral and corpus callosum atrophy. Molecular study with a leukodystrophy gene panela identified a homozygotic pathogenic variant on PEX 1 gene (NM_000466.3) - c.2528G>A (p.(Gly843Asp)), confirming the diagnosis of ZSD. Homozygosity for PEX1 p.Gly843Asp seems to be associated with an intermediate/milder ZSD phenotype,with survival until adulthood. Some patients develop progressive degeneration of CNS myelin, a leukodystrophy pattern, like this patient, which may lead to regression. This girl with ZSD had a rapid and severe loss of previous skills after a seizure. Even though there is no specific treatment for this disease, a correct diagnosiswas very important for the parents and for family genetic counselling.

SAT187 A Case Of CDC73 Mutation Related Primary Hyperparathyroidism With Ectopic Parathyroid Hyperplasia

Abstract Disclosure: T. Wu: None. N. Dhir: None. M. Bollineni: None. Introduction: Primary hyperparathyroidism is the most common cause of hypercalcemia, and most cases are sporadic. However, in 5-10% cases, it may occur as a syndromic and hereditary disease, like Multiple endocrine neoplasia type 1, type 2A, type 4, or CDC73 mutation related hereditary benign or malignant hyperparathyroidism. In patients with severe or early onset primary hyperparathyroidism, screening for genetic etiology should be considered. Case Presentation: A 35-year-old woman with a medical history of hypertension, kidney stones, and post-operative hypothyroidism presented to the endocrinology clinic due to recurrent hyperparathyroidism. She initially had a parathyroidectomy in 2008 and her calcium corrected at that time. She was again diagnosed with hypercalcemia due to primary hyperparathyroidism in 2021. She underwent re-exploration and had a right thyroid lobectomy with removal of three parathyroid glands. Her PTH was still 309 pg/mL (9-77 pg/mL) and calcium was 11.2 mg/dL (8.6-10.5 mg/dL), and she was started on Cinacalcet. The patient continued to have elevated calcium, bone pain, fatigue, and constipation. A 4D CT scan was ordered, which localized activity to a 1.5 cm arterial enhancing nodule in the anterior mediastinum, with intrathymic location. She underwent right video-assisted thoracoscopic total thymectomy with en bloc and the nodule was found to be ectopic parathyroid tissue. Post-operatively, her calcium normalized to 8.6 mg/dL and PTH was undetectable. She underwent genetic testing due to her recurrent hyperparathyroidism, which showed a CDC73 mutation. She is currently on calcitriol and calcium supplements, and serum calcium has been maintained in the low-normal range. Discussion: The CDC73 gene encodes a protein called parafibromin, which acts as a tumor suppressor, prohibiting cells from proliferating. Mutations in this gene are linked to jaw-tumor syndrome, familial isolated primary hyperparathyroidism (FIHP), and parathyroid carcinoma. These three CDC73-related disorders are clinically overlapping and inherited in an autosomal dominant manner. Biallelic mutations of the CDC73 gene are associated with a high risk of parathyroid cancer since the parafibromin protein is usually absent in parathyroid carcinoma and occasionally in atypical adenomas. FIHP tends to have a more severe clinical presentation with earlier onset (younger than 45 years). Additionally, patients with CDC73 related disorders are more prone to developing ossifying fibroma(s) of the jaw, uterine tumors, and various renal lesions. In summary, this case highlights the diagnostic and therapeutic challenges in a patient with persistent primary hyperparathyroidism after a failed second surgery. Genetic testing is vital for early detection, surveillance, and familial genetic counseling in patients with CDC73 related disorders. Presentation: Saturday, June 17, 2023