Absent tibia-polydactyly-arachnoid cyst syndrome, also known as Holmes-Collins syndrome, is a very rare multi-systemic hereditary disorder which is characterized by facial dysmorphisms,[1] pre/post-axial polydactyly, toe syndactyly, missing/underdeveloped tibia bone, and the presence of a retrocerebellar arachnoid cyst.[2][3][4] Additional findings include clubbed feet, cleft lip, diaphragm agenesis, and radial and ulnar anomalies.[5]
It was first discovered in 1995 by Holmes et al., when they described three siblings (one male and two females) born to consanguineous, first cousin once removed[6] parents with the symptoms mentioned above (including the additional ones), Holmes et al. did not find abnormalities in the HOXD10, HOXA9, and HOXC9 genes. They concluded this was part of a brand new (novel) autosomal recessive syndrome.[7]