Publications by authors named "Majdi Kara"

Pyridoxine-dependent epilepsy (PDE-ALDH7A1) is an autosomal recessive condition due to a deficiency of α-aminoadipic semialdehyde dehydrogenase, which is a key enzyme in lysine oxidation. PDE-ALDH7A1 is a developmental and epileptic encephalopathy that was historically and empirically treated with pharmacologic doses of pyridoxine. Despite adequate seizure control, most patients with PDE-ALDH7A1 were reported to have developmental delay and intellectual disability.

View Article and Find Full Text PDF

Asparaginyl-tRNA synthetase1 (NARS1) is a member of the ubiquitously expressed cytoplasmic Class IIa family of tRNA synthetases required for protein translation. Here, we identify biallelic missense and frameshift mutations in NARS1 in seven patients from three unrelated families with microcephaly and neurodevelopmental delay. Patient cells show reduced NARS1 protein, impaired NARS1 activity and impaired global protein synthesis.

View Article and Find Full Text PDF
Article Synopsis
  • * Researchers identified 32 individuals with microcephaly, neurodevelopmental issues, and other neurological symptoms due to mutations in NARS1, revealing reduced levels of NARS1 mRNA and enzyme activity in affected cells.
  • * The study suggests that these mutations lead to neurodevelopmental diseases through mechanisms like toxic gain-of-function for new mutations and partial loss-of-function for recessive mutations.
View Article and Find Full Text PDF

Neuronal migration defects, including pachygyria, are among the most severe developmental brain defects in humans. Here, we identify biallelic truncating mutations in CTNNA2, encoding αN-catenin, in patients with a distinct recessive form of pachygyria. CTNNA2 was expressed in human cerebral cortex, and its loss in neurons led to defects in neurite stability and migration.

View Article and Find Full Text PDF

Background: Aicardi-Goutières syndrome is a rare genetic neurological disorder with variable clinical manifestations. Molecular detection of specific mutations is required to confirm the diagnosis. The aim of this study was to review the clinical and molecular diagnostic findings in 24 individuals with Aicardi-Goutières syndrome who presented during childhood in an Arab population.

View Article and Find Full Text PDF

Autism spectrum disorders (ASD) are a group of genetic disorders often overlapping with other neurological conditions. We previously described abnormalities in the branched-chain amino acid (BCAA) catabolic pathway as a cause of ASD. Here, we show that the solute carrier transporter 7a5 (SLC7A5), a large neutral amino acid transporter localized at the blood brain barrier (BBB), has an essential role in maintaining normal levels of brain BCAAs.

View Article and Find Full Text PDF

Docosahexanoic acid (DHA) is the most abundant omega-3 fatty acid in brain, and, although it is considered essential, deficiency has not been linked to disease. Despite the large mass of DHA in phospholipids, the brain does not synthesize it. DHA is imported across the blood-brain barrier (BBB) through the major facilitator superfamily domain-containing 2a (MFSD2A) protein.

View Article and Find Full Text PDF

Hereditary spastic paraplegias (HSPs) are neurodegenerative motor neuron diseases characterized by progressive age-dependent loss of corticospinal motor tract function. Although the genetic basis is partly understood, only a fraction of cases can receive a genetic diagnosis, and a global view of HSP is lacking. By using whole-exome sequencing in combination with network analysis, we identified 18 previously unknown putative HSP genes and validated nearly all of these genes functionally or genetically.

View Article and Find Full Text PDF

Joubert syndrome and related disorders (JSRDs) are genetically heterogeneous and characterized by a distinctive mid-hindbrain malformation. Causative mutations lead to primary cilia dysfunction, which often results in variable involvement of other organs such as the liver, retina, and kidney. We identified predicted null mutations in CSPP1 in six individuals affected by classical JSRDs.

View Article and Find Full Text PDF

Autism spectrum disorders are a genetically heterogeneous constellation of syndromes characterized by impairments in reciprocal social interaction. Available somatic treatments have limited efficacy. We have identified inactivating mutations in the gene BCKDK (Branched Chain Ketoacid Dehydrogenase Kinase) in consanguineous families with autism, epilepsy, and intellectual disability.

View Article and Find Full Text PDF

Rotaviruses and noroviruses are leading viral causes of diarrhoea in children. A cross-sectional study was undertaken among children aged <5 years with acute gastroenteritis at Al-Jala Children's Hospital, Tripoli, Libya, from October 2007 to September 2008. Of 1,090 fecal samples collected, 260 from inpatients and 830 from outpatients, all inpatients and approximately a third of outpatients, selected systematically, were investigated for rotavirus and norovirus infection by ELISA and real-time RT-PCR, respectively.

View Article and Find Full Text PDF

Full text is available as a scanned copy of the original print version.

View Article and Find Full Text PDF