Tawfeg I Ben-Omran

Publications (2)4.78 Total impact

• Article: Late-onset cobalamin-C disorder: a challenging diagnosis.

  Tawfeg I Ben-Omran, Hubert Wong, Susan Blaser, Annette Feigenbaum
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  ABSTRACT: Cobalamin-C (cblC) disease is a rare autosomal recessive disorder due to defective intracellular cobalamin metabolism. There are few (13) reported patients of the late-onset presentation of cblC disease with paucity of detailed clinical descriptions. This results in this condition being easily missed. In this report, we describe clinical and biochemical findings of two unrelated patients with late-onset cblC disease who presented with neuropsychiatric symptoms. Serial MRI images are provided for one of these patients. Presumptive diagnosis was made with urine and plasma biochemical markers and confirmed with fibroblast analysis. These patients illustrate the challenging diagnosis of this disease and also report on the rare associated findings of vasculopathy and mitochondrial respiratory chain dysfunction. Mutation analysis of the MMACHC gene showed that both patients were homozygous for 394C --> T which suggests a founder effect.
  American Journal of Medical Genetics Part A 05/2007; 143A(9):979-84. · 2.39 Impact Factor
• Article: A patient with mutations in DNA Ligase IV: clinical features and overlap with Nijmegen breakage syndrome.

  Tawfeg I Ben-Omran, Karen Cerosaletti, Patrick Concannon, Sheila Weitzman, Marjan M Nezarati
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  ABSTRACT: The clinical phenotype of Ligase IV syndrome (LIG4 syndrome), an extremely rare autosomal recessive condition caused by mutations in the LIG4 gene, closely resembles that of Nijmegen breakage syndrome (NBS), and is characterized by microcephaly, characteristic facial features, growth retardation, developmental delay, and immunodeficiency. We report a 4(1/2)-year-old boy who presented with acute T-cell leukemia. The facial gestalt was strongly reminiscent of NBS. The patient died shortly after the onset of treatment for his T-cell leukemia. Subsequent chromosome breakage studies showed a high rate of breakage in a fibroblast culture. Radiosensitivity was assessed by a colony survival assay; the results showed radiosensitivity greater than is typically seen in NBS. Mutation screening of the NBS1 gene was negative. Sequencing of the LIG4 gene revealed a homozygous truncating mutation 2440 C>T (R814X). Although this mutation has been previously noted in LIG4 syndrome, this patient is the first reported homozygote for the mutation. In this study, we review the clinical features of this rare syndrome and provide suggestions for differential diagnosis.
  American Journal of Medical Genetics Part A 09/2005; 137A(3):283-7. · 2.39 Impact Factor