Biotinidase Deficiency and Aplasia Cutis Congenita with Ecterodactyly Syndrome (ACCES) in a case of Moya Moya Disease: A Missing Link

Biotinidase Deficiency (BD) is a rare autosomal recessive disorder caused by mutations in the BTD gene, leading to impaired biotin recycling and disruption in energy metabolism, oxidative stress, and blood-brain barrier function. This condition increases the risk of neurovascular events such as strokes. In parallel, the UBA2 gene's loss of function, through various mutations, results in Aplasia Cutis Congenita with Ectrodactyly (ACCES) syndrome, an autosomal dominant disorder with highly variable expressivity. ACCES syndrome commonly presents with scalp defects and less frequently with ectrodactyly, alongside other subtle skeletal anomalies, early growth deficiency, and neurodevelopmental delay. This case report discusses a 6-year-old child presenting with an acute stroke and distinct dysmorphic features, highlighting a rare association between Biotinidase Deficiency and ACCES syndrome, which likely contributed to the development of Moya Moya Disease (MMD), a rare progressive cerebrovascular disorder. The case suggests that the combination of neurovascular stress due to both BD and ACCES may increase the risk of stroke and MMD in affected individuals. This underscores the importance of recognizing overlapping genetic conditions that could lead to severe neurovascular complications.