Tay-Sachs Disease: Two Novel Rare HEXA Mutations from Pakistan and Morocco

2021 ◽  
Author(s):  
Farah Bibi ◽  
Asmat Ullah ◽  
Thomas Bourinaris ◽  
Stephanie Efthymiou ◽  
Yamna Kriouile ◽  
...  
Keyword(s):  
Genetic Disorder ◽  
Cost Effective ◽  
Genome Project ◽  
Causative Gene ◽  
Tay Sachs Disease ◽  
Clinical Investigations ◽  
Whole Exome ◽  
Hexosaminidase A ◽  
Pakistani Origin ◽  
Targeted Gene Sequencing

Abstract Background Tay-Sachs disease (TSD) is a rare autosomalrecessive genetic disorder characterized by progressive destruction of nerve cells in the brain and spinal cord. It is caused by genetic variations in the HEXA gene leading to a deficiency of β hexosaminidase A (HEXA) isoenzyme activity. This study aimed to identify causative gene variants in 3 unrelated consanguineous families presented with TSD from Pakistan and Morocco. Methods Detailed clinical investigations were carried out on probands in 3 unrelated consanguineous families of Pakistani and Moroccan origin. Targeted gene sequencing and Whole Exome Sequencing (WES) were performed for variant identification. Candidate variants were checked for co-segregation with the phenotype using Sanger sequencing. Public databases including ExAC, GnomAD, dbSNP and the 1,000 Genome Project were searched to determine frequencies of the alleles. Conservation of the missense variants was ensured by aligning orthologous protein sequences from diverse vertebrate species. Results We report on 3 children presented with Tay-Sachs Disease. The β hexosaminidaseA enzyme activity was reduced in the Pakistani patient in one of the pedigrees. Genetic testing revealed 2 novel homozygous variants (p.Asp386Alafs*13 and p.Trp266Gly) in the gene HEXA in Pakistani and Moroccan patients respectively.The third family of Pakistani origin revealed a previously reported variant (p.Tyr427Ilefs*5) in HEXA. p.Tyr427Ilefs*5 is the most commonly occurring pathogenic variationin Ashkenazi but was not reported in Pakistani population. Conclusion Our study further expands the ethnic and mutational spectrum of Tay-Sachs disease emphasizing the usefulness of WES as a powerful diagnostic tool where enzymatic activity is not performed for Tay-Sachs disease. The study recommends targeted screening for these mutations (p.Tyr427Ilefs5) for cost effective testing of TSD patients. Further, the study would assist in carrier testing and prenatal diagnosis of the affected families.

Article on Tay-Sachs Disease

2021 ◽  
pp. 475-478
Author(s):  
Bhawana. B. Bhende
Keyword(s):  
Autosomal Recessive ◽  
Genetic Disorder ◽  
Single Gene ◽  
Genetic Defect ◽  
Premature Death ◽  
Nerve Cells ◽  
Tay Sachs Disease ◽  
Hexosaminidase A ◽  
Physical Abilities ◽  
The Brain

Tay–Sachs disease is a genetic disorder that results in the destruction of nerve cells in the brain and spinal cord..also known as GM2 gangliosidosis or Hexosaminidase A deficiency) is an autosomal recessive genetic disorder. In its most common variant known as infantile Tay-Sachs disease it presents with a relentless deterioration of mental and physical abilities which commences at 6 months of age and usually results in death by the age of four.It is caused by a genetic defect in a single gene with one defective copy of that gene inherited from each parent. The disease occurs when harmful quantities of gangliosides accumulate in the nerve cells of the brain, eventually leading to the premature death of those cells. There is currently no cure or treatment. Tay- Sachs disease is a rare disease. Other autosomal disorders such as cystic fibrosis and sickle cell anemia are far more common. TSD is an autosomal recessive genetic disorder, meaning that when both parents are carriers, there is a 25% risk of giving birth to an affected child.

scholarly journals A Case Report of a Prenatally Missed Mowat-Wilson Syndrome With Isolated Corpus Callosum Agenesis

2021 ◽  
Vol 8 ◽  
pp. 2329048X2110065
Author(s):  
Nesrin Şenbil ◽  
Zeynep Arslan ◽  
Derya Beyza Sayın Kocakap ◽  
Yasemin Bilgili
Keyword(s):  
Corpus Callosum ◽  
Autosomal Dominant ◽  
Genetic Disorder ◽  
Gene Mutations ◽  
Hirschsprung Disease ◽  
Agenesis Of Corpus Callosum ◽  
Whole Exome ◽  
Congenital Cardiac Anomalies ◽  
History Of ◽  
Gene Mutation Analysis

Mowat–Wilson syndrome (MWS) is an autosomal dominant genetic disorder caused by ZEB2 gene mutations, manifesting with unique facial characteristics, moderate to severe intellectual problems, and congenital malformations as Hirschsprung disease, genital and ophthalmological anomalies, and congenital cardiac anomalies. Herein, a case of 1-year-old boy with isolated agenesis of corpus callosum (IACC) in the prenatal period is presented. He was admitted postnatally with Hirschsprung disease (HSCR), hypertelorism, uplifted earlobes, deeply set eyes, frontal bossing, oval-shaped nasal tip, ‘‘M’’ shaped upper lip, opened mouth and prominent chin, and developmental delay. Hence, MWS was primarily considered and confirmed by the ZEB2 gene mutation analysis. His karyotype was normal. He had a history of having a prenatally terminated brother with similar features. Antenatally detected IACC should prompt a detailed investigation including karyotype and microarray; even if they are normal then whole exome sequencing (WES) should be done.

scholarly journals Serum Cytokine Profile, Beta-Hexosaminidase A Enzymatic Activity and GM2 Ganglioside Levels in the Plasma of a Tay-Sachs Disease Patient after Cord Blood Cell Transplantation and Curcumin Administration: A Case Report

Life ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1007
Author(s):  
Alisa A. Shaimardanova ◽  
Daria S. Chulpanova ◽  
Valeriya V. Solovyeva ◽  
Ekaterina E. Garanina ◽  
Ilnur I. Salafutdinov ◽  
...  
Keyword(s):  
Blood Cell ◽  
Enzymatic Activity ◽  
Cord Blood ◽  
Cell Transplantation ◽  
Cytokine Profile ◽  
Serum Cytokine ◽  
Α Subunit ◽  
Cord Blood Cell ◽  
Tay Sachs Disease ◽  
Hexosaminidase A

Tay-Sachs disease (TSD) is a progressive neurodegenerative disorder that occurs due to a deficiency of a β hexosaminidase A (HexA) enzyme, resulting in the accumulation of GM2 gangliosides. In this work, we analyzed the effect of umbilical cord blood cell transplantation (UCBCT) and curcumin administration on the course of the disease in a patient with adult TSD. The patient’s serum cytokine profile was determined using multiplex analysis. The level of GM2 gangliosides in plasma was determined using mass spectrometry. The enzymatic activity of HexA in the plasma of the patient was assessed using a fluorescent substrate assay. The HexA α-subunit (HexA) concentration was determined using ELISA. It was shown that both UCBCT and curcumin administration led to a change in the patient’s cytokine profile. The UCBCT resulted in an increase in the concentration of HexA in the patient’s serum and in an improvement in the patient’s neurological status. However, neither UCBCT nor curcumin were able to alter HexA activity and the level of GM2 in patient’s plasma. The data obtained indicate that UCBCT and curcumin administration can alter the immunity of a patient with TSD, reduce the level of inflammatory cytokines and thereby improve the patient’s condition.

Cost Effectiveness of Whole Exome Sequencing for Children with Developmental Delay in a Developing Country: A Study from Jordan

2021 ◽  
Author(s):  
Amira Masri ◽  
Hanan Hamamy
Keyword(s):  
Cost Effectiveness ◽  
Exome Sequencing ◽  
Developmental Delay ◽  
Developing Country ◽  
Whole Exome Sequencing ◽  
Financial Burden ◽  
Indirect Costs ◽  
Cost Effective ◽  
Whole Exome ◽  
The Cost

AbstractThis retrospective study was aiming to determine the cost effectiveness of whole exome sequencing (WES) in the diagnosis of children with developmental delay in a developing country. In this study of 40 patients, the average cost of traditional investigations and indirect costs related to rehabilitation and medications per child were USD847 and 6,585 per year, respectively. With a current cost for WES of approximately USD1,200, we concluded that performing WES could be cost effective, even in countries with limited resources, as it provides the option for genetic counseling in affected families with an ultimate reduction of overall financial burden to both parents and health care system.

scholarly journals Pitt-Hopkins Syndrome: A Unique Case Study

2018 ◽  
Vol 24 (9) ◽  
pp. 995-1002 ◽  
Author(s):  
Alexander Tan ◽  
Kimberly Goodspeed ◽  
Veronica Bordes Edgar
Keyword(s):  
Cognitive Abilities ◽  
Genetic Disorder ◽  
Autism Spectrum ◽  
Fine Motor ◽  
Medical Comorbidities ◽  
Severe Intellectual Disability ◽  
Whole Exome ◽  
Independent Ambulation ◽  
Present Case Study

AbstractObjectives: Pitt-Hopkins syndrome (PTHS) is a rare genetic disorder caused by insufficient expression of the TCF4 gene. Most cases are characterized by severe intellectual disability, absent speech, motor delays, and autism spectrum disorder. Many have abnormal brain imaging, dysmorphic facial features, and medical comorbidities: myopia, constipation, epilepsy, and apneic spells. The present case study expands existing understanding of this disorder by presenting a unique phenotype with higher cognitive abilities and fewer medical comorbidities. Methods: The present case study reports on a 13-year-old, Caucasian male with a recent diagnosis of PTHS following genetic testing (i.e., whole exome sequencing). He was referred for a neuropsychological evaluation to document his neurocognitive functioning to assist with intervention planning. Results: Evaluation of intellectual, attention/executive, memory, visual-motor/fine-motor, academic, adaptive, and emotional/behavioral functioning revealed global impairment across all areas of functioning. However, he demonstrated abilities beyond what has been detailed in the literature, including use of full sentences, capacity to learn and solve novel problems, basic academic functioning, and independent ambulation. Conclusions: Children with PTHS may demonstrate a spectrum of abilities beyond what has been documented in the literature thus far. Failure to recognize this spectrum can result in late identification of an accurate diagnosis. (JINS, 2018, 24, 995–1002)

Direct-to-Consumer Genetic Testing

2011 ◽  
pp. 51-84 ◽  
Author(s):  
Richard A. Stein
Keyword(s):  
Human Genome ◽  
Human Genome Project ◽  
Cost Effective ◽  
Helical Structure ◽  
Genome Project ◽  
Next Generation ◽  
Double Helical Structure ◽  
Sequencing Technologies ◽  
Human Genome Sequencing ◽  
The Human Genome Project

The 1953 discovery of the DNA double-helical structure by James Watson, Francis Crick, Maurice Wilkins, and Rosalind Franklin, represented one of the most significant advances in the biomedical world (Watson and Crick 1953; Maddox 2003). Almost half a century after this landmark event, in February 2001, the initial draft sequences of the human genome were published (Lander et al., 2001; Venter et al., 2001) and, in April 2003, the International Human Genome Sequencing Consortium reported the completion of the Human Genome Project, a massive international collaborative endeavor that started in 1990 and is thought to represent the most ambitious undertaking in the history of biology (Collins et al., 2003; Thangadurai, 2004; National Human Genome Research Institute). The Human Genome Project provided a plethora of genetic and genomic information that significantly changed our perspectives on biomedical and social sciences. The sequencing of the first human genome was a 13-year, 2.7-billion-dollar effort that relied on the automated Sanger (dideoxy or chain termination) method, which was developed in 1977, around the same time as the Maxam-Gilbert (chemical) sequencing, and subsequently became the most frequently used approach for several decades (Sanger et al., 1975; Maxam & Gilbert, 1977; Sanger et al., 1977). The new generations of DNA sequencing technologies, known as next-generation (second generation) and next-next-generation (third generation) sequencing, which started to be commercialized in 2005, enabled the cost-effective sequencing of large chromosomal regions during progressively shorter time frames, and opened the possibility for new applications, such as the sequencing of single-cell genomes (Service, 2006; Blow, 2008; Morozova and Marra, 2008; Metzker, 2010).

Whole exome and targeted gene sequencing to detect pathogenic recessive variants in early onset cerebellar ataxia

2019 ◽  
Vol 96 (6) ◽  
pp. 566-574
Author(s):  
Sunil Shakya ◽  
Renu Kumari ◽  
Varun Suroliya ◽  
Nishu Tyagi ◽  
Aditi Joshi ◽  
...  
Keyword(s):  
Cerebellar Ataxia ◽  
Early Onset ◽  
Gene Sequencing ◽  
Whole Exome ◽  
Targeted Gene Sequencing

scholarly journals Case report: targeted whole exome sequencing enables the first prenatal diagnosis of the lethal skeletal dysplasia Osteocraniostenosis

2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Lara Pemberton ◽  
Robert Barker ◽  
Anna Cockell ◽  
Vijaya Ramachandran ◽  
Andrea Haworth ◽  
...  
Keyword(s):  
Case Report ◽  
Prenatal Diagnosis ◽  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Skeletal Dysplasia ◽  
Genetic Disorder ◽  
Specific Gene ◽  
Ultrasound Images ◽  
Whole Exome ◽  
Lethal Skeletal Dysplasia

Abstract Background Osteocraniostenosis (OCS) is a rare genetic disorder characterised by premature closure of cranial sutures, gracile bones and perinatal lethality. Previously, diagnosis has only been possible postnatally on clinical and radiological features. This study describes the first prenatal diagnosis of OCS. Case presentation In this case prenatal ultrasound images were suggestive of a serious but non-lethal skeletal dysplasia. Due to the uncertain prognosis the parents were offered Whole Exome Sequencing (WES), which identified a specific gene mutation in the FAMIIIa gene. This mutation had previously been detected in two cases and was lethal in both perinatally. This established the diagnosis, a clear prognosis and allowed informed parental choice regarding ongoing pregnancy management. Conclusions This case report supports the use of targeted WES prenatally to confirm the underlying cause and prognosis of sonographically suspected abnormalities.

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