I am a clinical genetics and genomics specialist. My focus is on congenital malformation syndromes, chromosomal disorders, Skeletal dysplasia and other genetic bone disorders, microarray and exome sequencing analyses, autistic spectrum disorders, metabolic disorders, newborn screen for inborn error of metabolism.
Rare de novo mutations have been implicated as a significant cause of idiopathic intellectual dis... more Rare de novo mutations have been implicated as a significant cause of idiopathic intellectual disability. Large deletions encompassing 10p11.23 have been implicated in developmental delay, behavioural abnormalities and dysmorphic features, but the genotype-phenotype correlation was not delineated. Mutations in WAC have been recently reported in large screening cohorts of patients with intellectual disability or autism, but no full phenotypic characterisation was described. Clinical and molecular characterisation of six patients with loss-of-function WAC mutations identified by whole exome sequencing was performed. Clinical data were obtained by retrospective chart review, parental interviews, direct patient interaction and formal neuropsychological evaluation. Five heterozygous de novo WAC mutations were identified in six patients. Three of the mutations were nonsense, and two were frameshift; all are predicted to cause loss of function either through nonsense-mediated mRNA decay or protein truncation. Clinical findings included developmental delay (6/6), hypotonia (6/6), behavioural problems (5/6), eye abnormalities (5/6), constipation (5/6), feeding difficulties (4/6), seizures (2/6) and sleep problems (2/6). All patients exhibited common dysmorphic features, including broad/prominent forehead, synophrys and/or bushy eyebrows, depressed nasal bridge and bulbous nasal tip. Posteriorly rotated ears, hirsutism, deep-set eyes, thin upper lip, inverted nipples, hearing loss and branchial cleft anomalies were also noted. Our case series show that loss-of-function mutations in WAC cause a recognisable genetic syndrome characterised by a neurocognitive phenotype and facial dysmorphism. Our data highly suggest that WAC haploinsufficiency is responsible for most of the phenotypic features associated with deletions encompassing 10p11.23.
The identification of the molecular basis of mitochondrial disorders continues to be challenging ... more The identification of the molecular basis of mitochondrial disorders continues to be challenging and expensive. The increasing usage of next-generation sequencing is facilitating the discovery of the genetic aetiology of heterogeneous phenotypes associated with these conditions. Coenzyme Q10 (CoQ10) is an essential cofactor for mitochondrial respiratory chain complexes and other biochemical pathways. Mutations in genes involved in CoQ10 biosynthesis cause primary CoQ10 deficiency syndromes that can be treated with oral supplementation of ubiquinone. We used whole exome sequencing to evaluate six probands from four unrelated families with clinical findings suggestive of a mitochondrial disorder. Clinical data were obtained by chart review, parental interviews, direct patient assessment and biochemical and pathological evaluation. We identified five recessive missense mutations in COQ4 segregating with disease in all four families. One mutation was found in a homozygous state in two u...
Developmental epilepsies are age-dependent seizure disorders for which genetic causes have been i... more Developmental epilepsies are age-dependent seizure disorders for which genetic causes have been increasingly identified. Here we report six unrelated individuals with mutations in salt-inducible kinase 1 (SIK1) in a series of 101 persons with early myoclonic encephalopathy, Ohtahara syndrome, and infantile spasms. Individuals with SIK1 mutations had short survival in cases with neonatal epilepsy onset, and an autism plus developmental syndrome after infantile spasms in others. All six mutations occurred outside the kinase domain of SIK1 and each of the mutants displayed autophosphorylation and kinase activity toward HDAC5. Three mutations generated truncated forms of SIK1 that were resistant to degradation and also showed changes in sub-cellular localization compared to wild-type SIK1. We also report the human neuropathologic examination of SIK1-related developmental epilepsy, with normal neuronal morphology and lamination but abnormal SIK1 protein cellular localization. Therefore, ...
American journal of medical genetics. Part A, 2015
NGLY1-related disorder is a newly described autosomal recessive condition characterized by neurol... more NGLY1-related disorder is a newly described autosomal recessive condition characterized by neurological, hepatic, ophthalmological findings and associated with dysmorphic features, constipation and scoliosis. It is caused by mutations in NGLY1, which encodes an enzyme, N-glycanase 1, involved in deglycosylation of glycoproteins, an essential step in the endoplasmic reticulum-associated degradation (ERAD) pathway. The disorder has been described in eight patients. We investigated the molecular basis and phenotype of NGLY1-related disorder in an additional patient. The proband is a 14-year-old who presented in early infancy with profound hypotonia and elevated transaminases. Liver biopsy showed lipid accumulation with dilated endoplasmic reticulum. He exhibited global developmental delay, acquired microcephaly, seizures, involuntary body movements, muscle atrophy, absent reflexes, and poor growth. He had multiple procedures for lacrimal duct stenosis and strabismus and had intractable...
The Israel Medical Association journal : IMAJ, 2003
Page 1. Case Communications Infantile Familial Mediterranean Fever Riva Brik MD, Marwan Shinawi M... more Page 1. Case Communications Infantile Familial Mediterranean Fever Riva Brik MD, Marwan Shinawi MD and Ruth Gershoni-Baruch MD ... Most patients begin to suffer during child-hood ± 60% before the age of 10 and 90% before age 20. ...
Familial Mediterranean fever (FMF) is an autosomal recessive disorder characterized by attacks of... more Familial Mediterranean fever (FMF) is an autosomal recessive disorder characterized by attacks of fever, serositis, and a predisposition to the development of amyloidosis. The wide clinical variability of the disease has been partly attributed to MEFV allelic heterogeneity and partly to the influence of additional genetic and/or environmental modifiers. Of these, male sex was found to influence disease penetrance and susceptibility to amyloidosis. We investigated the role of sex as an independent contributor to the phenotypic profile in FMF and further defined the factors affecting disease expression and severity. A total of 124 patients with FMF who were all homozygous for the M694V mutation, including 47 patients with nephropathic amyloidosis, were identified. A detailed chart review and physical examination were undertaken to determine demographic characteristics, history, clinical manifestations, and treatment, and we calculated the disease severity score from the Tel-Hashomer k...
Familial Mediterranean fever (FMF) is an autosomal recessive disease that primarily affects non-A... more Familial Mediterranean fever (FMF) is an autosomal recessive disease that primarily affects non-Ashkenazi Jews, Armenians, Arabs, and Turks. The FMF (MEFV) gene responsible for the disease has been recently identified. Four missense mutations in exon 10 of the FMF gene seem to account for 86% of the DNA variations identified in patients with FMF. We conducted a phenotype/genotype correlation study in a homogenous population of Israeli-Moslem Arab patients with FMF and performed a mutational screening analysis on DNA samples from healthy individuals of this ethnic group. Sixty-five patients clinically diagnosed as having FMF underwent molecular genetic studies using polymerase chain reaction and restriction endonuclease digestion methods to detect the presence of the 4 mutations (M694V, V726A, M680I, M694I). We then correlated the presence of each mutation with age of onset, clinical manifestations, and disease severity; patients whose allelic combination included M694V were then exc...
Rare de novo mutations have been implicated as a significant cause of idiopathic intellectual dis... more Rare de novo mutations have been implicated as a significant cause of idiopathic intellectual disability. Large deletions encompassing 10p11.23 have been implicated in developmental delay, behavioural abnormalities and dysmorphic features, but the genotype-phenotype correlation was not delineated. Mutations in WAC have been recently reported in large screening cohorts of patients with intellectual disability or autism, but no full phenotypic characterisation was described. Clinical and molecular characterisation of six patients with loss-of-function WAC mutations identified by whole exome sequencing was performed. Clinical data were obtained by retrospective chart review, parental interviews, direct patient interaction and formal neuropsychological evaluation. Five heterozygous de novo WAC mutations were identified in six patients. Three of the mutations were nonsense, and two were frameshift; all are predicted to cause loss of function either through nonsense-mediated mRNA decay or protein truncation. Clinical findings included developmental delay (6/6), hypotonia (6/6), behavioural problems (5/6), eye abnormalities (5/6), constipation (5/6), feeding difficulties (4/6), seizures (2/6) and sleep problems (2/6). All patients exhibited common dysmorphic features, including broad/prominent forehead, synophrys and/or bushy eyebrows, depressed nasal bridge and bulbous nasal tip. Posteriorly rotated ears, hirsutism, deep-set eyes, thin upper lip, inverted nipples, hearing loss and branchial cleft anomalies were also noted. Our case series show that loss-of-function mutations in WAC cause a recognisable genetic syndrome characterised by a neurocognitive phenotype and facial dysmorphism. Our data highly suggest that WAC haploinsufficiency is responsible for most of the phenotypic features associated with deletions encompassing 10p11.23.
The identification of the molecular basis of mitochondrial disorders continues to be challenging ... more The identification of the molecular basis of mitochondrial disorders continues to be challenging and expensive. The increasing usage of next-generation sequencing is facilitating the discovery of the genetic aetiology of heterogeneous phenotypes associated with these conditions. Coenzyme Q10 (CoQ10) is an essential cofactor for mitochondrial respiratory chain complexes and other biochemical pathways. Mutations in genes involved in CoQ10 biosynthesis cause primary CoQ10 deficiency syndromes that can be treated with oral supplementation of ubiquinone. We used whole exome sequencing to evaluate six probands from four unrelated families with clinical findings suggestive of a mitochondrial disorder. Clinical data were obtained by chart review, parental interviews, direct patient assessment and biochemical and pathological evaluation. We identified five recessive missense mutations in COQ4 segregating with disease in all four families. One mutation was found in a homozygous state in two u...
Developmental epilepsies are age-dependent seizure disorders for which genetic causes have been i... more Developmental epilepsies are age-dependent seizure disorders for which genetic causes have been increasingly identified. Here we report six unrelated individuals with mutations in salt-inducible kinase 1 (SIK1) in a series of 101 persons with early myoclonic encephalopathy, Ohtahara syndrome, and infantile spasms. Individuals with SIK1 mutations had short survival in cases with neonatal epilepsy onset, and an autism plus developmental syndrome after infantile spasms in others. All six mutations occurred outside the kinase domain of SIK1 and each of the mutants displayed autophosphorylation and kinase activity toward HDAC5. Three mutations generated truncated forms of SIK1 that were resistant to degradation and also showed changes in sub-cellular localization compared to wild-type SIK1. We also report the human neuropathologic examination of SIK1-related developmental epilepsy, with normal neuronal morphology and lamination but abnormal SIK1 protein cellular localization. Therefore, ...
American journal of medical genetics. Part A, 2015
NGLY1-related disorder is a newly described autosomal recessive condition characterized by neurol... more NGLY1-related disorder is a newly described autosomal recessive condition characterized by neurological, hepatic, ophthalmological findings and associated with dysmorphic features, constipation and scoliosis. It is caused by mutations in NGLY1, which encodes an enzyme, N-glycanase 1, involved in deglycosylation of glycoproteins, an essential step in the endoplasmic reticulum-associated degradation (ERAD) pathway. The disorder has been described in eight patients. We investigated the molecular basis and phenotype of NGLY1-related disorder in an additional patient. The proband is a 14-year-old who presented in early infancy with profound hypotonia and elevated transaminases. Liver biopsy showed lipid accumulation with dilated endoplasmic reticulum. He exhibited global developmental delay, acquired microcephaly, seizures, involuntary body movements, muscle atrophy, absent reflexes, and poor growth. He had multiple procedures for lacrimal duct stenosis and strabismus and had intractable...
The Israel Medical Association journal : IMAJ, 2003
Page 1. Case Communications Infantile Familial Mediterranean Fever Riva Brik MD, Marwan Shinawi M... more Page 1. Case Communications Infantile Familial Mediterranean Fever Riva Brik MD, Marwan Shinawi MD and Ruth Gershoni-Baruch MD ... Most patients begin to suffer during child-hood ± 60% before the age of 10 and 90% before age 20. ...
Familial Mediterranean fever (FMF) is an autosomal recessive disorder characterized by attacks of... more Familial Mediterranean fever (FMF) is an autosomal recessive disorder characterized by attacks of fever, serositis, and a predisposition to the development of amyloidosis. The wide clinical variability of the disease has been partly attributed to MEFV allelic heterogeneity and partly to the influence of additional genetic and/or environmental modifiers. Of these, male sex was found to influence disease penetrance and susceptibility to amyloidosis. We investigated the role of sex as an independent contributor to the phenotypic profile in FMF and further defined the factors affecting disease expression and severity. A total of 124 patients with FMF who were all homozygous for the M694V mutation, including 47 patients with nephropathic amyloidosis, were identified. A detailed chart review and physical examination were undertaken to determine demographic characteristics, history, clinical manifestations, and treatment, and we calculated the disease severity score from the Tel-Hashomer k...
Familial Mediterranean fever (FMF) is an autosomal recessive disease that primarily affects non-A... more Familial Mediterranean fever (FMF) is an autosomal recessive disease that primarily affects non-Ashkenazi Jews, Armenians, Arabs, and Turks. The FMF (MEFV) gene responsible for the disease has been recently identified. Four missense mutations in exon 10 of the FMF gene seem to account for 86% of the DNA variations identified in patients with FMF. We conducted a phenotype/genotype correlation study in a homogenous population of Israeli-Moslem Arab patients with FMF and performed a mutational screening analysis on DNA samples from healthy individuals of this ethnic group. Sixty-five patients clinically diagnosed as having FMF underwent molecular genetic studies using polymerase chain reaction and restriction endonuclease digestion methods to detect the presence of the 4 mutations (M694V, V726A, M680I, M694I). We then correlated the presence of each mutation with age of onset, clinical manifestations, and disease severity; patients whose allelic combination included M694V were then exc...
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