Homozygous Deletion Of Exon Research Articles

The functional state of the respiratory system of the patients with proximal spinal muscular atrophy 5q (SMA 5q): from the natural history of the disease to the era of pathogenetic therapy. Problems and expectations

Proximal spinal muscular atrophy 5q is an autosomal recessive neuromuscular disease. This disorder is characterized by progressive symptoms of flaccid paralysis and muscular atrophy due to degeneration of α-motor neurons in the anterior horns of the spinal cord. The disease is caused by the lack of a fully functional SMN protein due to homozygous deletion of exon 7 in the SMN1 gene. For a long time, spinal muscular atrophy was the leading genetic cause of infant mortality. With the introduction of modern pathogenetic treatment methods that modify the disease, the duration and quality of life of patients increases, and a “blurring of boundaries” between types of spinal muscular atrophy and the formation of new phenotypes happens. In this regard, approaches to patient management, including approaches to the assessment and correction of respiratory disorders, are changing. The review of the available medical literature was conducted. The clinical studies on spinal muscular atrophy in the natural course of the disease and with the use of pathogenetic drugs were analyzed, as well as the data on the state of the respiratory system of the patients.

Current Treatment Process and Challenges for Spinal Muscular Atrophy (SMA)

Spinal muscular atrophy (SMA) presents as a pediatric neuromuscular disorder resulting from mutations in the survival motor neuron 1(SMN1) gene, with an incidence of approximately 10-13 per 100,000 live births. This condition manifests primarily through muscle weakness and atrophy, particularly affecting the proximal limb muscles. A homozygous deletion of exon 7 in the SMN1 gene is the most common genetic mutation in SMA and serves as a sensitive diagnostic marker. This article comprehensively explores various aspects of SMA, including its types, diagnostic methods, and management strategies. Pulmonary care, gastrointestinal (GI) management, nutritional supplementation, orthopedic spinal care, and physiotherapy play crucial roles in delaying disease progression. Current pharmacological treatments for SMA are diverse and evolving. Notable among them is Zolgensma (formerly AVXS-101 or Onasemnogene abeparvovec), a gene replacement therapy utilizing an adeno-associated virus vector to boost functional SMN protein levels. Sodium vanadate, a phosphatase inhibitor, and risdiplam (RO703406) are agents that modulate SMN2 splicing to augment the production of functional SMN protein. Riluzole acts as a neuroprotective agent by preventing SMN deficiency, while reldesemtive (CK-2127107) is under development as a muscle-enhancing therapy to ameliorate skeletal muscle function during fatigue. While pharmacological therapies for SMA are advancing, a holistic approach involving comprehensive multidisciplinary care, encompassing pulmonary support, proper nutritional supplementation, and adept orthopedic management, significantly contributes to the effective management of SMA.

Analysis of single nucleotide polymorphism of p16 gene in cytological samples of patients with oral potentially malignant disorders (OPMD) and oral squamous cell carcinoma (OSCC)

Backgroundpl6 (CDKN2a) play a role in tumorigenesis in some head and neck squamous cell carcinomas. Frequent homozygous deletions of the pl6 gene have been reported in many tumor cell lines including the brain, breast, osteosarcomas, melanomas, kidney, bladder, and ovary. Materials and methods5 patients without any tobacco using habit were included in group I as controls. 10 clinically and histopathologically confirmed cases of oral potentially malignant disorders (OPMDs) [oral submucous fibrosis (OSMF) −7 & leukoplakia (moderate dysplasia) −3] were included in group II. 10 clinically and histopathologically confirmed cases of OSCC were categorized as group III. Buccal scrapings were taken and analyzed for exon 1, 2, 3 of p16 and homozygous deletion in exon 2 of p16 was also detected by PCR and gel electrophoresis. ResultsPCR amplification products of exon 1, 2, 3 of p16 were found in all 25 samples which include 10 cases of OSCC, 10 cases of OPMDs and 5 controls. Homozygous deletion in exon 2 was found only in 30 % of OSCC and 20 % of OPMD. ConclusionOur study showed that cytological samples yield sufficient amount of DNA, which showed 100 % positivity with exon 1, 2, 3 of p16 gene, but the percentage of genetic alteration of p16 gene seems to be less when compared with other related studies.

Biallelic Deletion of PEX26 Exon 4 in a Boy with Phenotypic Features of both Zellweger Syndrome and Infantile Refsum Disease

Introduction: Peroxisome biogenesis disorders (PBDs) encompass a group of diseases marked by clinical and genetic heterogeneity. Phenotypes linked to PBDs include Zellweger syndrome, neonatal adrenoleukodystrophy, infantile Refsum disease (IRD), rhizomelic chondrodysplasia punctata type 1, and Heimler syndrome. PBD phenotypes manifest through hypotonia, developmental delay, facial dysmorphism, seizures, liver dysfunction, sensorineural hearing loss, and retinal dystrophy. Methods: The proband underwent comprehensive clinical evaluation, followed by whole-exome sequencing (WES) coupled with copy number analysis (CNV), aimed at identifying potential disease-causing variants aligning with the observed phenotype. Results: Our findings detail an individual exhibiting developmental delay, hearing loss, visual impairment, hepatomegaly, and splenomegaly, attributed to a biallelic deletion of exon 4 in the PEX26 gene. The WES analysis of the index case did not uncover any pathogenic/likely pathogenic single-nucleotide variations that could account for the observed clinical findings. However, the CNV data derived from WES revealed a homozygous deletion in exon 4 of the PEX26 gene (NM_001127649.3), providing a plausible explanation for the patient’s clinical features. The exon 4 region of PEX26 encodes the transmembrane domain of the protein. The transmembrane domain plays a crucial role in anchoring the protein within lipid bilayers, and its absence can disrupt proper localization and functioning. As a result, this structural alteration may impact the protein’s ability to facilitate essential cellular processes related to peroxisome biogenesis and function. Conclusion: The index patient, which presented with hearing loss, retinal involvement and hepatic dysfunction in adolescence age, has atypical clinical course that can be considered unusual for Zellweger syndrome (ZS) and IRD phenotypes, and its rare genotypic data (in-frame single exon deletion) expands the PBD disease spectrum. This study revealed for the first time that PEX26 protein transmembrane domain loss exhibits an unusual course with clinical findings of IRD and ZS phenotypes. WES studies, incorporating CNV analyses, empower the identification of novel genetic alterations in genes seldom associated with gross deletion/duplication variations, such as those in the PEX26 gene. This not only enhances diagnostic rates in rare diseases but also contributes to broadening the spectrum of causal mutations.

Documentation of a novel FBP1 gene mutation in the Arabian ethnicity: a case report

BackgroundFructose-1,6-bisphosphatase deficiency is a rare autosomal recessive disorder characterized by impaired gluconeogenesis. Fructose-1,6-bisphosphatase 1 (FBP1) mutations demonstrate ethnic patterns. For instance, Turkish populations commonly harbor exon 2 deletions. We present a case report of whole exon 2 deletion in a Syrian Arabian child as the first recording of this mutation among Arabian ethnicity and the first report of FBP1 gene mutation in Syria.Case presentationWe present the case of a 2.5-year-old Syrian Arab child with recurrent hypoglycemic episodes, accompanied by nausea and lethargy. The patient’s history, physical examination, and laboratory findings raised suspicion of fructose-1,6-bisphosphatase deficiency. Whole exome sequencing was performed, revealing a homozygous deletion of exon 2 in the FBP1 gene, confirming the diagnosis.ConclusionThis case highlights a potential novel mutation in the Arab population; this mutation is well described in the Turkish population, which suggests potential shared mutations due to ancestral relationships between the two ethnicities. Further studies are needed to confirm this finding.

Screening of Spinal Muscular Atrophy Carriers and Prenatal Diagnosis in Pregnant Women in Yancheng, China.

Spinal muscular atrophy (SMA) is a neuromuscular disorder with an autosomal recessive inheritance pattern. Patients with severe symptoms may suffer respiratory failure, leading to death. The homozygous deletion of exon 7 in the SMN1 gene accounts for nearly 95% of all cases. Population carrier screening for SMA and prenatal diagnosis by amniocentesis for high-risk couples can assist in identifying the risk of fetal disease. We provided the SMA carrier screening process to 55,447 pregnant women in Yancheng from October 2020 to December 2022. Among them, 8185 participated in this process, with a participation rate of around 14.76% (95% CI 14.47-15.06%). Quantitative real-time polymerase chain reaction (qPCR) was used to detect deletions of SMN1 exons 7 and 8 (E7, E8) in screened pregnant women. 127 were identified as carriers (111 cases of E7 and E8 heterozygous deletions, 15 cases of E7 heterozygous deletions, and 1 case of E7 heterozygous deletions and E8 homozygous deletions), resulting in a carrying rate of around 1.55% (95% CI 1.30-1.84%). After genetic counseling, 114 spouses of pregnant women who tested positive underwent SMA carrier screening; three of them were screened as SMA carriers. Multiplexed ligation-dependent probe amplification (MLPA) was used for the prenatal diagnosis of the fetuses of high-risk couples. Two of them exhibited two copies of SMN1 exon 7 (normal), and the pregnancy was continued; one exhibited no copies of SMN1 exon 7 and exon 8 (SMA patient), and the pregnancy was terminated. Analyzing SMN1 mutations in Yancheng and provide clinical evidence for SMA genetic counseling and birth defect prevention. Interventional prenatal diagnosis for high-risk families can promote informed reproductive selection and prepare for the fetus's early treatment.

Long term clinical follow up of four patients with Wolfram syndrome and urodynamic abnormalities.

Wolfram syndrome is characterised by insulin-dependent diabetes (IDDM), diabetes insipidus (DI), optic atrophy, sensorineural deafness and neurocognitive disorders. The DIDMOAD acronym has been recently modified to DIDMOAUD suggesting the rising awareness of the prevalence of urinary tract dysfunction (UD). End stage renal disease is the commonest cause of mortality in Wolfram syndrome. We present a case series with main objective of long term follow up in four children having Wolfram syndrome with evaluation of their urodynamic profile. A prospective follow up of four genetically proven children with Wolfram syndrome presenting to a tertiary care pediatric diabetes clinic in Pune, India was conducted. Their clinical, and urodynamic parameters were reviewed. IDDM, in the first decade, was the initial presentation in all the four children (three male and one female). Three children had persistent polyuria and polydipsia despite having optimum glycemic control; hence were diagnosed to have DI and treated with desmopressin. All four patients entered spontaneous puberty. All patients had homozygous mutation in WFS1 gene; three with exon 8 and one with exon 6 novel mutations. These children with symptoms of lower urinary tract malfunction were further evaluated with urodynamic studies; two of them had hypocontractile detrusor and another had sphincter-detrusor dyssynergia. Patients with hypocontractile bladder were taught clean intermittent catheterization and the use of overnight drain. We report a novel homozygous deletion in exon 6 of WFS-1 gene. The importance of evaluation of lower urinary tract malfunction is highlighted by our case series. The final bladder outcome in our cases was a poorly contractile bladder in three patients.

Optimized MLPA workflow for spinal muscular atrophy diagnosis: identification of a novel variant, NC_000005.10:g.(70919941_70927324)del in isolated exon 1 of SMN1 gene through long-range PCR

BackgroundSpinal muscular atrophy (SMA) is a rare autosomal recessive hereditary neuromuscular disease caused by survival motor neuron 1 (SMN1) gene deletion or mutation. Homozygous deletions of exon 7 in SMN1 result in 95% of SMA cases, while the remaining 5% are caused by other pathogenic variants of SMN1.MethodsWe analyzed two SMA-suspected cases that were collected, with no SMN1 gene deletion and point mutation in whole-exome sequencing. Exon 1 deletion of the SMN gene was detected using Multiplex ligation-dependent probe amplification (MLPA) P021. We used long-range polymerase chain reaction (PCR) to isolate the SMN1 template, optimized-MLPA P021 for copy number variation (CNV) analysis within SMN1 only, and validated the findings via third-generation sequencing.ResultsTwo unrelated families shared a genotype with one copy of exon 7 and a novel variant, g.70919941_70927324del, in isolated exon 1 of the SMN1 gene. Case F1-II.1 demonstrated no exon 1 but retained other exons, whereas F2-II.1 had an exon 1 deletion in a single SMN1 gene. The read coverage in the third-generation sequencing results of both F1-II.1 and F2-II.1 revealed a deletion of approximately 7.3 kb in the 5’ region of SMN1. The first nucleotide in the sequence data aligned to the 7385 bp of NG_008691.1.ConclusionRemarkably, two proband families demonstrated identical SMN1 exon 1 breakpoint sites, hinting at a potential novel mutation hotspot in Chinese SMA, expanding the variation spectrum of the SMN1 gene and corroborating the specificity of isolated exon 1 deletion in SMA pathogenesis. The optimized-MLPA P021 determined a novel variant (g.70919941_70927324del) in isolated exon 1 of the SMN1 gene based on long-range PCR, enabling efficient and affordable detection of SMN gene variations in patients with SMA, providing new insight into SMA diagnosis to SMN1 deficiency and an optimized workflow for single exon CNV testing of the SMN gene.

КЛИНИЧЕСКИЙ СЛУЧАЙ БОЛЕЗНИ КУГЕЛЬБЕРГА-ВЕЛАНДЕРА (СПИНАЛЬНОЙ МЫШЕЧНОЙ АТРОФИИ III ТИПА)

Background. Differential diagnosis of neuromuscular diseases is one of the most difficult areas in neurology. Molecular genetic research in these patients is of particular importance. The article presents a clinical case of 5q spinal muscular atrophy type III (Kugelberg – Welander disease), confirmed by molecular genetic testing. Description of the clinical case. The article presents the clinical observation of a patient with an initial diagnosis of Erb – Roth myopathy. A genetic study was carried out. The analysis of the presence of exon 7 of the SMN1/SMN2 genes showed the absence of a signal corresponding to exon 7 of the SMN1 gene. A search for deletions in the SMN1 gene showed the homozygous deletion of exons 7–8 of the SMN1 gene in the proband. Homozygous deletion of exons 7–8 of the SMN1 gene causes 5q proximal spinal muscular atrophy. As a result of determining the num-ber of copies of the SMN1 and SMN2 genes, 0 copies of exons 7–8 of the SMN1 gene and 4 copies of exons 7–8 of the SMN2 gene were registered, which confirms the diagnosis of 5q spinal muscular atrophy type III. Conclusion. Adult patients suffering from neuromuscular diseases are recommended to undergo confirmatory DNA diagnostics to prescribe pathogenetic treatment, which increases their chances of survival. In young people with a clinical diagnosis of neuromuscular disease, genetic testing is required to clarify the diagnosis and further treatment tactics.

Establishment of a Pilot Newborn Screening Program for Spinal Muscular Atrophy in Saint Petersburg.

Spinal muscular atrophy 5q (SMA) is one of the most common neuromuscular inherited diseases and is the most common genetic cause of infant mortality. SMA is associated with homozygous deletion of exon 7 in the SMN1 gene. Recently developed drugs can improve the motor functions of infants with SMA when they are treated in the pre-symptomatic stage. With aim of providing an early diagnosis, newborn screening (NBS) for SMA using a real-time PCR assay with dried blood spots (DBS) was performed from January 2022 through November 2022 in Saint Petersburg, which is a representative Russian megapolis. Here, 36,140 newborns were screened by the GenomeX real-time PCR-based screening test, and three genotypes were identified: homozygous deletion carriers (4 newborns), heterozygous carriers (772 newborns), and wild-type individuals (35,364 newborns). The disease status of all four newborns that screened positive for the homozygous SMN1 deletion was confirmed by alternate methods. Two of the newborns had two copies of SMN2, and two of the newborns had three copies. We determined the incidence of spinal muscular atrophy in Saint Petersburg to be 1 in 9035 and the SMA carrier frequency to be 1 in 47. In conclusion, providing timely information regarding SMN1, confirmation of disease status, and SMN2 copy number as part of the SMA newborn-screening algorithm can significantly improve clinical follow-up, testing of family members, and treatment of patients with SMA.

Analysis of SMN1, NAIP and GTF2H2 gene status in correlation with spinal muscular atrophy

Introduction. Spinal Muscular Atrophy (SMA) is a genetic disorder caused by the loss of the survival motor neuron (SMN1) gene in over 95% of cases. Additionally, mutations in genes associated with the SMA chromosomal region can influence disease progression. Aim: To analyze the status of the NAIP and GTF2H2 genes in correlation with SMA. Material and methods. The study included 105 patients suspected for SMA of which 50 with confirmed with SMA and 55 without causative deletions, and 107 healthy, unrelated individuals. The molecular genetics methods used were mPCR, PCR-RFLP and MLPA. Results. From 105 patients, 50 were confirmed with SMA. In this group were identified in 8 patients (16%) with a homozygous deletion of exon 5 of the NAIP gene, 4 patients (8%) had a heterozygous status, and 2 (4%) had duplications. In the rest of the patients (55), in which deletions of SMN1 exon 7 were not identified, homozygous deletion of exon 5 of the NAIP gene was established in one patient (2%), 3 patients (5%) had duplications of exon 5 of the NAIP gene, and one patient had 5 copies of the NAIP gene. In the 107 healthy controls, one patient (1%) was identified with a deletion of exon 5 of the NAIP gene. None of the patients with combined deletions of SMN1 and NAIP had deletions in GTF2H2. Conclusions. The frequency of deletions in the NAIP gene was found to be higher in the SMA patient group compared to the control group. Thus, a significant relationship was identified, the P value being <0.00001. The significance threshold was set at p<0.05. The genetic patterning of genes associated with SMA is an important aspect in the study of molecular pathophysiology and assessment of disease prognosis, especially in the approach to gene therapies.

A new line method; A direct test in spinal muscular atrophy screening for DBS.

Nucleic acid-based assays provide an opportunity to screen for genetically encoded diseases like spinal muscular atrophy (SMA), before the onset of symptoms. Nowadays, such assays could be easily utilized as high-throughputs in SMA to detect a homozygous deletion of exon 7 of the survival motor neuron 1 gene (SMN1) that is responsible for >95% of SMA patients. We developed a new line method (NLM) as a direct real time PCR test procedure without nucleic acid extraction in dried blood spots (DBS) to screen for homozygous deletion of exon 7 of the SMN1 gene. Performance of this setup was evaluated on 580 DBS newborn samples and air dried 50 DBS from whole blood including 20 samples for homozygous deletion of the SMN1 gene detected earlier with MLPA. We found all 580 newborn DBS samples as wild type. DBS prepared from 50 whole blood samples also including 20 affected people were correctly identified as homozygous deletions and 30 wild types of exon 7 of SMN1 as before with MLPA. When the MLPA method was taken as the gold standard, the sensitivity and specificity of the NLM test were found 100% for the detection of SMN1 exon 7 homozygous deletion. In the NLM, the total test duration has been reduced to less than 75 min without requiring any extra process such as DNA extraction step and sample plate preparation after the punching step. Thereby, newborn SMA screening with the NLM has gained an environmentally friendly feature with not requiring additional tedious steps.

The Puzzle of Perlman: A Rare Overgrowth Syndrome

Perlman syndrome is a rare overgrowth syndrome characterized by increased body size, specific dysmorphic features, and association with neurodevelopmental disorders, kidney disease, and risk of Wilms tumor. This autosomal recessive syndrome is usually caused by homozygous defects in DIS3 L2. Few cases survive beyond the neonatal period. We present a Saudi male infant who was evaluated for visceromegaly. Antenatal ultrasound revealed an enlarged kidney. Postnatally, the patient required prolonged hospitalization for birth asphyxia. Facial dysmorphism included low-set ears, depressed nasal bridge, tented upper lip, micrognathia, and a high forehead. Follow-up ultrasound indicated bilateral round kidney masses, suggesting Wilms tumor. Genetic testing revealed a homozygous deletion in exon 9 of DIS3 L2. The patient survived the first 2 years of life. Patients with Perlman syndrome require a multidisciplinary approach to long-term management.

P.072 Alberta Spinal Muscular Atrophy Newborn Screening (SMA-NBS) – 2022 results

Background: Spinal muscular atrophy (SMA) is a progressive neuromuscular disease caused by biallelic mutations of the survival motor neuron 1 (SMN1) gene. Early diagnosis via newborn screening and presymptomatic treatment are essential to optimize health outcomes for affected individuals. Methods: We developed a multiplex real-time polymerase chain reaction assay using dried blood spot samples for the detection of homozygous deletion of exon 7 of the SMN1 gene. Newborns who were screened positive were seen urgently for clinical evaluations. Copy numbers of SMN1 and SMN2 genes were determined by multiplex ligation-dependent probe amplication for confirmatory testing. Results: From February 28, 2022 to December 31, 2022, 42,450 newborns were screened in Alberta. Four infants had abnormal screen results and were subsequently confirmed to have SMA. No false positive newborns were detected. Three infants received adeno-associated virus serotype 9 (AAV9)-mediated SMN1 gene replacement therapy <31 days of age. One infant received SMN2-splicing modulator treatment due to maternally-transferred AAV9 neutralizing antibodies prior to gene therapy at 3 months of age. Conclusions: The estimated incidence of SMA in Alberta is 9.4 (95% CI: 2.5 – 24.1) per 100,000 live-births. During the first year of the SMA-NBS program, 4 asymptomatic infants received treatment and demonstrated excellent developmental progress to date.

Abstract #1408177: Spinal Muscle Atrophy Presenting with Non-Diabetic Ketoacidosis

Spinal muscle atrophy (SMA) is an untreatable neurodegenerative disease related to loss of survival motor neuron (SMN) 1 gene resulting in muscle atrophy leading to significant morbidity and mortality. Patients with SMA may present with metabolic disturbances including impaired glucose tolerance, fatty acid metabolism and hyperlipidemia. We present a case of SMA presenting with recurrent metabolic acidosis. 51-year-old female with hypertension, osteoporosis, and SMA (homozygous deletion of exon 7 in the SMN1 gene) with quadriplegia and chronic ventilator dependent respiratory failure was admitted with diarrhea, poor oral intake, nausea, and abdominal pain. She did not report sick contacts or fever and had no history of diabetes. She had similar past episodes of metabolic acidosis with acute illness. Vital signs were BP 135/74mmHg, HR 110/min, RR 20/min, afebrile, and SpO2 96% on room air. On exam she appeared ill and debilitated with dry oral mucosa, + abdominal distension and tenderness with no rebound. Labs showed anion gap metabolic acidosis, Na 136mEq/L, K 3.9mEq/L, Cl 102 mEq/L, CO2 12 mEq/L, Anion gap 22, pH 7.13, Creatinine <0.01mg/dl, glucose 110 mg/dl, 2+ urine ketones, beta hydroxybutyrate 7.39 mmol/L, WBC 23.97 K/ul and HbA1c 5.2%. She was treated for non-diabetic ketoacidosis with IV fluids and fixed dose IV insulin infusion with dextrose infusion in tandem. She had hypernatremia, hypocalcemia, hypophosphatemia and hypokalemia likely due to poor nutrition and dehydration, and with aggressive electrolyte replacement, she showed significant clinical improvement during hospitalisation. Patients with SMA are prone to metabolic derangements e.g. ketoacidosis. Several factors may contribute to ketoacidosis such as decreased muscle mass, defects in endocrine pancreatic function and abnormal fatty acid metabolism regardless of triggering factors. One study investigated glucose metabolism and pancreas development in the Smn (2B/-) intermediate SMA mouse model and type I SMA patients. In mice it demonstrated a dramatic cell fate imbalance within pancreatic islets, with a predominance of glucagon-producing α cells at the expense of insulin-producing β cells and mice displayed fasting hyperglycemia, hyperglucagonemia, and glucose resistance. Similar abnormalities in pancreatic islet cells were seen in deceased children with the severe infantile form of SMA indicating that defects in glucose metabolism may play an important contributory role in SMA pathogenesis. There are no present guidelines to manage this entity, but case reports indicated a role of volume resuscitation and electrolyte replacement for improvement and future prevention by avoiding fasting.

Fasting Dependent Paroxysmal Exercise Induced Dystonia as Presenting Symptom in PRKN Type of Parkinson's Disease.

Paroxysmal exercise-induced dystonia (PED) can occur as a symptom of early-onset Parkinson's disease (EOPD), Dopa-responsive dystonia (DRD), or Glut1 deficiency syndrome (Glut1DS). Red flags of PED in Glut1DS include influence of diet, while diurnal fluctuations are characteristic for DRD.1 A 22-year-old White-European man presented with a 5-year history of paroxysmal involuntary movements of his left foot. Past medical history and family history were unremarkable without known consanguinity. At the age of 17 (BMI 38 kg/m2), he started a diet and regular physical exercise and lost 35 kg weight. After approximately 30 min of physical exercise, he occasionally noticed mild and involuntary abnormal posturing of his left foot. Symptoms only occurred in the evening or after fasting. Since then, symptoms have worsened, and abnormal movements started after 15 min of exercise in the morning and after 5 min in the evening or when fasting. Recently, he also noticed a mild tremor and clumsiness of his right hand. Physical examination revealed mild rigidity of neck and extremities, mild resting tremor of the right hand and mild bradykinesia of upper and lower limbs (right dominant). He had reduced arm swing, but otherwise walking was unremarkable (see Video 1). After 10 min of running, he developed dystonia of his left foot (see Video 2), which ceased shortly after resting. A 3-Tesla-MRI of the brain, CSF/serum fasting glucose ratio and a metabolic panel including blood/CSF amino acids and neurotransmitters were unremarkable. A (123)I-Ioflupane single-photon emission computed tomography was abnormal. A genetic panel including known genes causing EOPD, DRD and Glut1DS was ordered. Both next generation sequencing and exon-specific PCR detected a homozygous deletion of exons 2–4 of the PRKN gene. Levodopa/benserazide 50/12.5 mg QID led to marked improvement of parkinsonian symptoms and PED. To the best of our knowledge, this is the first reported case of the PRKN type of EOPD featuring PED with marked diurnal fluctuation and worsening with fasting as presenting symptom. In 16% of PRKN mutation carriers symptoms start in adolescence.2 Initial foot dystonia, in some cases induced by exercise,1, 3 and diurnal fluctuation are recognized features.4 However, symptom provocation by fasting is a novel finding. The products of several PD-associated genes including PRKN have important roles in mitochondrial biology and fasting induces an upregulation of protein markers of mitophagy. Our patient noticed remission of PED with regular carbohydrate intake. A low protein-to-carbohydrate ratio has been shown to increase lifespan, motor ability and mitochondrial function in a PRKN mutant Drosophila model of PD,5 providing a potential pathophysiological link to our finding. A deletion of exons represents the most common mutation of the PRKN gene; deletions of exons 2–4 are classified as definitely pathogenic.2 Another reported case presenting with juvenile-onset PED had a deletion of exon 4.3 Worsening with fasting was neither described in a published case series4 nor in patients with deletions of exons 2–4 of the PRKN gene within the MDS gene database. In conclusion, diurnally fluctuating PED that worsens with carbohydrate restriction may be the presenting symptom in the PRKN type of EOPD. We would like to thank our patient for giving us the opportunity to publish this case report. We also thank Johann Semmler-Bruckner for his assistance in genetic analyses and database research. 1. Research project: A. Conception, B. Organization, C. Execution; 2. Data Collection: A. Clinical Assessment, B. Genetic Analysis, C. Literature Review; 3. Manuscript Preparation: A. Writing of the first draft, B. Review and Critique. L.G.: 1B, 1C, 2A, 2C, 3A C.W.: 1B, 1C, 2B, 3B P.K.W.: 1B, 1C, 2A, 3B P.S.: 1A, 1B, 1C, 2A, 2C, 3B Ethical Compliance Statement: No formal approval by an ethics committee was required; the Journal's Ethical Publication guidelines and the Declaration of Helsinki were followed. Informed written consent on video acquisition and case publication was obtained from the patient using our standardized patient's video consent form. We confirm that we have read the Journal's position on issues involved in ethical publication and affirm that this work is consistent with those guidelines. Funding Sources and Conflicts of Interest: No specific funding was received for this work. The authors declare that there are no conflicts of interest relevant to this work. Financial Disclosures for Previous 12 Months: L. Gattermeyer, C. Windpassinger and P. Katschnig-Winter declare that there are no additional disclosures to report. P. Schwingenschuh reports personal fees from Bial.

Detection of pathogenic variants in four patients with globozoospermia

To explore the genetic basis for 4 patients with globozoospermia. Semen and blood samples were collected from the patients for the determination of sperm concentration, viability, survival rate, morphology and acrosome antigen CD46. Meanwhile, DNA was extracted for whole exome sequencing (WES), and candidate variants were validated by Sanger sequencing. All of the four patients were found to harbor variants of the DPY19L2 gene. Patients 1 ~ 3 had homozygous deletions of the DPY19L2 gene. Sanger sequencing confirmed that the DPY19L2 gene in patient 3 was disrupted at a recombination breakpoint area BP2, resulting in nonallelic homologous recombination and complete deletion of the DPY19L2 gene. Patients 2 and 3 respectively harbored novel homozygous deletions of exons 2 ~ 22 and exons 14 ~ 15. Patient 4 harbored heterozygous deletion of the DPY19L2 gene, in addition with a rare homozygous deletion of the 3' UTR region. DPY19L2 gene variants probably underlay the globozoospermia in the four patients, which has fit an autosomal recessive pattern of inheritance and the characteristics of genomic diseases.

Extended analysis of exome sequencing data reveals a novel homozygous deletion of exons 3 and 4 in FUCA1 gene causing fucosidosis in an Indian family.

do Rosario, Michelle C.a; Purushothama, Greeshmaa; Narayanan, Dhanya Lakshmia,b; Siddiqui, Shahyanc; Girisha, Katta Mohana; Shukla, Anjua Author Information

A comprehensive overview of SMN and NAIP copy numbers in Iranian SMA patients

Spinal muscular atrophy (SMA) is among the most common autosomal recessive disorders with different incidence rates in different ethnic groups. In the current study, we have determined SMN1, SMN2 and NAIP copy numbers in an Iranian population using MLPA assay. Cases were recruited from Genome-Nilou Laboratory, Tehran, Iran and Pars-Genome Laboratory, Karaj, Iran during 2012–2022. All enrolled cases had a homozygous deletion of exon 7 of SMN1. Moreover, except for 11 cases, all other cases had a homozygous deletion of exon 8 of SMN1. Out of 186 patients, 177 (95.16%) patients showed the same copy numbers of exons 7 and 8 of SMN2 gene. In addition, 53 patients (28.49%) showed 2 copies, 71 (38.17%) showed 3 copies and 53 patients (28.49%) showed 4 copies of SMN2 gene exons 7 and 8. The remaining 9 patients showed different copy numbers of exons 7 and 8 of SMN2 gene. The proportions of SMA patients with different numbers of normal NAIP were 0 copy in 73 patients (39.24%), 1 copy in 59 patients (31.72%), 2 copies in 53 patients (28.49%) and 4 copies in one patient (0.5%). These values are different from values reported in other populations. Integration of the data of the SMN1/2 and NAIP genes showed 17 genotypes. Patients with genotype 0-0-3-3-1 (0 copies of SMN1 (E7,8), 3 copies of SMN2 (E7,8) and 1 copy of NAIP (E5)) were the most common genotype in this study. Patients with 0-0-2-2-0 genotype were more likely to have type I SMA. The results of the current study have practical significance, particularly in the genetic counseling of at-risk families.

Spinal muscular atrophy with hypoplasia of the corpus callosum: a case report

BackgroundSpinal Muscular Atrophy (SMA) is a severe neuromuscular disorder due to a defect in the survival motor neuron 1 (SMN1) gene. Hypoplasia of the corpus callosum is underdevelopment or thinness of the corpus callosum. SMA and callosal hypoplasia are relatively rare, and there is limited information sharing the diagnosis and treatment for SMA patients with callosal hypoplasia.Case descriptionA boy with callosal hypoplasia, small penis, and small testes had been perceived with motor regression at 5 months. He was referred to the rehabilitation department and neurology department at 7 months. Physical examination showed absent deep tendon reflexes, proximal weakness and significant hypotonia. He was recommended to perform trio whole-exome sequencing (WES) and array comparative genomic hybridization (aCGH) for his complicated conditions. The subsequent nerve conduction study revealed some characteristics of motor neuron diseases. We identified a homozygous deletion in exon 7 of the SMN1 gene by multiplex ligation-dependent probe amplification and failed to find further pathogenic variations responsible for multiple malformations by trio WES and aCGH. He was diagnosed as SMA. Despite some concerns, he received the therapy of nusinersen for nearly 2 years. He gained the milestone of sitting without support, which he had never accomplished, after the seventh injection, and he continued to improve. During follow-up, there were no adverse events reported and no signs of hydrocephalus.ConclusionsSome extra features which could not belong to neuromuscular manifestation made the diagnosis and treatment of SMA more complicated.