A novel PGAP3 mutation in a Croatian boy with brachytelephalangy and a thin corpus callosum

Biallelic mutations in the post-GPI attachment to proteins 3 ( PGAP3 ) gene cause hyperphosphatasia with mental retardation syndrome 4 (HPMRS4), which is characterized by elevated serum alkaline phosphatase, severe psychomotor developmental delay, seizures, and facial dysmorphism. To date, 15 PGAP3 mutations have been reported in humans. Here we report a novel homozygous PGAP3 mutation (c.314C>A, p.Pro105Gln) in a Croatian patient and fully describe the clinical features.