875 BIOTINIDASE DEFICIENCY DETECTED BY A STATEWIDE NEONATAL SCREENING PROGRAM

Abstract

Biotinidase deficiency is an autosomal recessively inherited disorder that usually manifests during infancy or early childhood with seizures, skin rash, alopecia, hearing loss, developmental delay and metabolic compromise, and occasionally results in coma and death. If diagnosed early the disorder can be treated effectively with biotin. To estimate the incidence of biotinidase deficiency and the potential cost-effectiveness of neonatal screening we conducted a pilot program in the Commonwealth of Virginia. After screening 77,145 newborns in ten months we have confirmed the diagnosis in two infants: a female and a male ascertained at 4 mos. and 2 mos. of age, respectively. Each infant had normal EEGs and developmental milestones, and neither had cutaneous or metabolic abnormalities. However, both were slightly hypertonic with brisk reflexes, and the female had abnormal brainstem auditory evoked potentials. Treatment with biotin (10 mg/d) was initiated within 3 days of confirming the diagnosis. Our preliminary estimate of the incidence of the disorder is 1 in 38,500 (95% confidence limits: 1 in 11,700 and 1 in 228,000). Affected infants are not symptomatic at birth, but may develop physical and neurologic abnormalities if untreated. The qualitative screening test for biotinidase activity is simple and inexpensive. Therefore, we recommend that testing for biotinidase deficiency be incorporated into all newborn screening programs.