Background: Molybdenum cofactor deficiency (MoCD) is a group of three autosomal recessive disorders caused by deficiency of the de novo metabolic synthesis of molybdenum cofactor. Most patients present within the first weeks of life with intractable seizures and progressive encephalopathy. Type A is the most common form caused by pathogenic variants in MOCS1 gene that result in deficiency of the first enzyme, cyclic pyranopterin monophosphate synthase.
Objectives: To characterize MoCD type A clinical features, disease course, neuroradiology, and genetic features in Northern Israel.
Methods: In this retrospective study, we collected the clinical, brain imaging, and genetic data of confirmed MoCD type A patients in Northern Israel.
Results: The study included 10 confirmed MoCD type A patients (6 males, 4 females), all deceased. The patients were of consanguineous families. Nine patients were of Arab Muslim ethnicity and one was of Druze origin. A total of four different homozygous genotypes were identified. All patients presented initially between 1–4 days of life. Three died within the first month of life, five within the first year of life, and only two died after the age of 7 years. All patients who survived beyond the first month developed profound global developmental delays, had poorly controlled epilepsy, and developed severe microcephaly.
Conclusions: Although MoCD type A is an ultra-rare disease worldwide, it is relatively common in northern Israel due to several founder mutations and high consanguinity. All the patients presented the severe neonatal form of the disease with significant neurological deterioration and early lethality within infancy and childhood.