We describe a 3-year-old son with biotin dependency not caused by biotinidase, holocarboxylase synthetase, or nutritional biotin deficiency. his PBMCs transformed with Epstein Barr virus were about 10% of normal fresh and transformed control cells, respectively. For fresh and transformed PBMCs from his parents, biotin uptake rates were consistent with heterozygosity for an autosomal recessive… Continue reading We describe a 3-year-old son with biotin dependency not caused by