Sarar Mohamed

A novel mutation and first report of dilated cardiomyopathy in ALG6-CDG (CDG-Ic): a case report

Congenital disorders of glycosylation (CDG) are an expanding group of inherited metabolic diseases with multisystem involvement. ALG6-CDG (CDGIc) is an endoplasmatic reticulum defect in N-glycan assembly. It is usually milder than PMM2-CDG (CDG-Ia) and so is its natural course. It is characterized by psychomotor retardation, seizures, ataxia, and hypotonia. In contrast to PMM2-CDG (CDGIa), there is no cerebellar hypoplasia. Cardiomyopathy has been reported in a few CDG types and in a number of patients with unexplained CDG. We report an 11 year old Saudi boy with severe psychomotor retardation, seizures, strabismus, inverted nipples, dilated cardiomyopathy, and a type 1 pattern of serum transferrin isoelectrofocusing. Phosphomannomutase and phosphomannose isomerase activities were normal in fibroblasts. Full gene sequencing of the ALG6 gene revealed a novel mutation namely c.482A>G (p.Y161C) and heterozygosity in the parents. This report highlights the importance to consider CDG in the differential diagnosis of unexplained cardiomyopathy.

A multicenter clinical exome study in unselected cohorts from a consanguineous population of Saudi Arabia demonstrated a high diagnostic yield

Abstract Purpose Whole-exome sequencing (WES) can help identify known and novel pathogenic molecular aberrations. Here, we examined the diagnostic yield of WES in population from consanguineous unions. Methods We preformed retrospective review of multicenter WES results of an unselected cohort of patients with a wide range of phenotypes. Clinical data and WES reports of 454 patients from 5 centers across Saudi Arabia were analyzed. Testing was performed in accredited commercial laboratories, and all the WES laboratory reports were reviewed again using additional clinical information available to the treating physicians. Results Among the 454 probands, we identified highly likely disease-causing variants in 222, thereby achieving a 49% molecular diagnostic yield. The diagnostic yield was 53% in consanguineous unions and 39% in non-consanguineous unions. About 66% of the identified variants in consanguineous families were homozygous, with an autosomal recessive mode of inheritance. Additional clinical data reclassified 11 positive reported results into 4 inconclusive and 7 negative results, and 22 inconclusive results into 17 positive and 5 negative results. Conclusions The diagnostic yield from WES in our unselected cohort is similar to other studies from the same region, which is a higher yield compared to other international regions largely because of the high rate of consanguinity and partly due to simplified variant interpretation and classification in consanguineous unions.

Congenital toxoplasmosis presenting as central diabetes insipidus in an infant: a case report

BackgroundCongenital toxoplasmosis has a wide range of presentation at birth varying from severe neurological features such as hydrocephalus and chorioretinitis to a well appearing baby, who may develop complications late in infancy. While neuroendocrine abnormalities associated with congenital toxoplasmosis are uncommon, isolated central diabetes insipidus is extremely rare.Case presentationHere, we report on a female infant who presented with fever, convulsions, and polyuria. Examination revealed weight and length below the 3rd centile along with signs of severe dehydration. Fundal examination showed bilateral chorioretinitis. This infant developed hypernatremia together with increased serum osmolality and decreased both urine osmolality and specific gravity consistent with central diabetes insipidus. Serology for toxoplasma specific immunoglobulin M was high for both the mother and the baby and polymerase chain reaction for toxoplasma deoxyribonucleic acid was positive in the infant confirming congenital toxoplasmosis. Brain computerized tomography scans demonstrated ventriculomegaly associated with cerebral and cortical calcifications. Fluid and electrolyte abnormalities responded to nasal vasopressin therapy.ConclusionThis report highlights central diabetes inspidus as a rare presentation of congenital toxoplasmosis.

Tyrosinemia type 1: a rare and forgotten cause of reversible hypertrophic cardiomyopathy in infancy.

BackgroundTyrosinemia type 1 (TT1) is an autosomal recessive disorder caused by deficiency of the enzyme fumarylacetoacetate hydrolase (FAH). TT1 usually presents in infancy with features suggestive of liver disease or with sepsis-like symptoms.Case presentationWe report two Saudi siblings with TT1. Case 1 was a male infant who presented at 2 months old with fever, vomiting and refusal of feeding. Examination revealed a sick-looking infant with signs of severe dehydration and hypovolemic shock. He was jaundiced, and had hepatomegaly and elevated liver enzymes. Echocardiography was performed in light of a lack of response to inotropes, and revealed biventricular and interventricular septal hypertrophies. The ventricular ejection fraction was 65%. Urine organic acid analysis showed elevated succinylacetone, consistent with a diagnosis of TT1. An FAH gene study identified a c.1 A > G homozygous mutation. This patient responded well to intensive cardiorespiratory therapy, tyrosine-free formula, and oral 2-nitro-4- trifluoromethylbenzyl 1, 3 cyclohexanedione (NTBC). Echocardiographic findings reverted to normal after 4 weeks. Case 2 was the younger brother of Case 1, and was born 6 months after his brother had been confirmed with tyrosinemia. Pregnancy and delivery were uneventful. Serum amino acid and organic acid analyses 4 days after birth confirmed tyrosinemia. DNA analysis identified a c.1 A > G homozygous mutation, as in his brother. Echocardiography was normal. Special formula and NTBC were commenced on day 7 of life. The infant remained asymptomatic after 9 months of follow-up.ConclusionsThese cases highlight TT1 as a treatable cause of cardiomyopathy in children. It also supports the idea that early diagnosis and treatment may prevent the development of cardiomyopathy associated with tyrosinemia.

Mode of initial presentation and chromosomal abnormalities in Irish patients with Turner syndrome: a single-centre experience.

Abstract Background: Age at diagnosis of girls with Turner syndrome (TS) is an important indicator of successful management. We determined the age, initial clinical presentation, and chromosomal abnormalities in patients with TS. Methods: This was a retrospective evaluation of the clinical and laboratory records of patients with TS. Results: Sixty-five patients with TS were identified; 40 (62%) were diagnosed after age 5 years. The main presenting features were short stature, delayed puberty, dysmorphic features, and neonatal lymphoedema. Chromosomal analysis of this cohort showed that 31 patients demonstrated mosaicism, while a 45,X karyotype was observed in 19. The remaining patients had variable abnormalities including deletion, translocation, isochromosome, and ring chromosome. Y-chromosome material was found in four cases. Conclusions: Most patients with TS were diagnosed after age 5 years, had a varied clinical presentation, and had a wide range of chromosomal abnormalities.

Screening for genetic mutations in LDLR gene with familial hypercholesterolemia patients in the Saudi population.

Familial hypercholesterolemia (FH) is caused by genetic defects involving the low density lipoprotein-receptor (LDL-R), predisposing affected people to premature atherosclerotic cardiovascular disease and death. The aim of the present study was to assess certain exons in the LDLR gene mutation detection analysis affecting in the Saudi population with FH. This case-control study was carried out with 200 subjects; 100 were FH cases and 100 were healthy controls. Five mL of venous blood samples were collected from all the subjects and used for biochemical and genetic analysis. DNA was extracted from 2 mL of the EDTA samples, and precise primers were designed for LDL-R gene which includes Exon 3, 4 and 8. PCR was followed by DNA sequencing. In our study, we found 25 mutations in cases in Exon-3 and 2 mutations in controls, however, we have found only 5 mutations in exon 4 and none of the mutations were identified in exon 8. We conclude that screening of FH among Saudi population is very important to identify individuals who are prone to develop the disease.

Association of angiotensin converting enzyme gene insertion/deletion polymorphism and familial hypercholesterolemia in the Saudi population.

BackgroundThe study of the association between genotype and phenotype is of great importance for the prediction of multiple diseases and pathophysiological conditions. The relationship between angiotensin converting enzyme (ACE) Insertion/Deletion (I/D) polymorphism and Familial Hypercholesterolemia (FH) has been not fully investigated in all the ethnicities. In this study we sought to determine the frequency of I/D polymorphism genotypes of ACE gene in Saudi patients with FH.ResultsThis is a case–control study carried out purely in Saudi population. Genomic DNA was isolated from 128 subjects who have participated in this study. ACE gene I/D polymorphism was analyzed by polymerase chain reaction in 64 FH cases and 64 healthy controls. There was no statistically significant difference between the groups with respect to genotype distribution. Furthermore, we did not find any significant difference in the frequency of ACE I/D polymorphism in FH subjects when stratified by gender (p = 0.43).ConclusionOur data suggest that ACE gene I/D polymorphism examined in this study has no role in predicting the occurrence and diagnosis of FH.

A Mutation in PEX19 Causes a Severe Clinical Phenotype in a Patient With Peroxisomal Biogenesis Disorder

Peroxisomal biogenesis disorders (PBD) are groups of inherited neurometabolic disorders caused by defects in PEX genes. We report on a female infant, born to a consanguineous parents (first degree cousins), who presented with inactivity, poor sucking, and hypotonia early in the neonatal period. She had subtle dysmorphic features. Liver function tests were impaired with raised liver enzymes, conjugated and unconjugated hyperbilirubinemia. CT of the brain showed diffuse bilateral changes. She developed seizures with an abnormal EEG. Plasma very long chain fatty acid analysis showed high C26:0 levels and increasedC26:0/C22:0 and C24:0/C22:0 ratios, which is consistent with a PBD. Studies in fibroblasts including plasmalogen biosynthesis, peroxisomal fatty acid alfa and beta oxidation confirmed the diagnosis of PBD. Immunofluoresence microscopy revealed the absence of peroxisomes in fibroblasts. The patient was assigned to the PEX19 complementation group. Subsequent mutation analysis of the PEX19 gene revealed homozygosity for a c.320delA frameshift mutation. The patient had a stormy course with multiple admissions to the pediatric intensive care unit with pneumonia, liver impairment, sepsis, and epilepsy. At 1 year of age she developed metabolic acidosis with normal anion gap, proteinuria, aminoaciduria, and glucosuria consistent with a renal tubular defect. Abdominal ultrasound showed multiple gallstones. Other causes of gallstones like haemoglobinopathy were excluded. So far, only two siblings had been reported with mutations in the PEX19 gene. Our patient showed a previously unrecognized association of gallstones and a renal tubular defect with a PBD.

A CYP21A2 gene mutation in patients with congenital adrenal hyperplasia: Molecular genetics report from Saudi Arabia

Objectives: The aim of this study is to determine congenital adrenal hyperplasia (CAH) with the pattern of CYP21A2 gene-mutations in Saudi children. Methods: Between January 2011 and March 2014 at King Fahad Military Complex, Dhahran, Saudi Arabia, we thoroughly examined 11 patients with CAH and 2 asymptomatic individuals with a history of affected siblings. Additionally, we sequenced the full coding regions of the CYP21A2 gene and screened the gene for deletion(s)/duplication(s) using the multiplex ligation-dependent probe amplification (MLPA) technique. Results: Nine patients had classic CAH and presented with ambiguous genitalia and/or salt losing crisis. Two patients had the non-classic form of CAH and presented with precocious puberty. The remaining 2 subjects were asymptomatic. Screening the CYP21A2 gene, we detected p.Gln318X mutation in 4 patients, c.290 -13 C>G (IVS2-13C>G) in another 4, and a common deletion, involving exons 6 and 8 in 3 patients. Conclusion: Our strategy of Sanger sequencing followed by MLPA was very successful in detecting CYP21A2 mutations in all patients with CAH.

Sanfilippo syndrome, glucose-6-phosphate dehydrogenase deficiency and sickle cell/β+ thalassemia in a child: The burden of consanguinity

Conflict of interest: none. Grant sponsor: College of Medicine Research Center; Grant sponsor: Deanship of Scientific Research; Grant sponsor: King Saud University Saudi Arabia. Correspondence to: Sarar Mohamed, FRCPCH, MD, Department of Pediatrics (39), College of Medicine, King Saud University, Riyadh 11461, PO Box 2925, Saudi Arabia. E-mail: sararmohamed@hotmail.com Article first published online in Wiley Online Library (wileyonlinelibrary.com): 12 September 2013 DOI 10.1002/ajmg.a.36180 TO THE EDITOR: