molybdenum-cofactor and Developmental-Disabilities

Molybdenum cofactor (MoCo) deficiency is a rare autosomal recessive inherited metabolic disorder resulting in the combined deficiency of aldehyde oxidase, xanthine dehydrogenase, and sulfite oxidase. We report a male infant with MoCo deficiency whose clinical findings consisted of microcephaly, intractable seizures soon after birth, feeding difficulties, and developmental delay. Sequencing of MOCS1, MOCS2, and GEPH genes, and single nucleotide polymorphism genotyping array analysis showed, to our knowledge, unusual inheritance of MoCo deficiency/maternal uniparental isodisomy for the first time in the literature. At 10 months of age, he now has microcephaly and developmental delay, and his seizures are controlled with phenobarbital, clonozepam, and vigabatrin therapy.

Topics: Carbon-Carbon Lyases; Carrier Proteins; Coenzymes; Developmental Disabilities; Feeding Behavior; Female; Humans; Infant; Male; Membrane Proteins; Metabolism, Inborn Errors; Metalloproteins; Microcephaly; Molybdenum Cofactors; Mothers; Nuclear Proteins; Polymorphism, Single Nucleotide; Pteridines; Seizures; Sulfurtransferases; Uniparental Disomy

Molybdenum cofactor deficiency was diagnosed in a 3-month-old girl who presented with microcephaly, developmental delay, severe irritability, and lactic acidosis. Dietary methionine restriction, with cysteine supplementation, was associated with moderate short-term clinical improvement, including a resumption in predicted head growth, modest developmental progress, and a reduction in irritability. Clinical relapse was associated with noncompliance of dietary therapy 2 months later. Urinary sulfite levels measured by commercial dipsticks were useful in following therapy. Molybdenum cofactor deficiency is probably frequently underdiagnosed due to the lack of specific clinical or laboratory features. Screening of infants at risk for the presence of urinary sulfites or serum hypouricemia, or both, is both rapid and inexpensive.

Topics: Acidosis, Lactic; Coenzymes; Cysteine; Developmental Disabilities; Female; Food, Fortified; Humans; Infant; Lactates; Metabolism, Inborn Errors; Metalloproteins; Methionine; Microcephaly; Molybdenum Cofactors; Pteridines