Macrostomia, thin upper vermilion border, long philtrum, broad halluces, and intellectual disability in two sibs

We report on two sibs with marked global developmental delay, hearing loss, unusual facial morphology (hypertelorism, long philtrum, exaggerated cupid bow upper lip, thin upper vermilion, large mouth), and broad halluces which were partly bifid on radiographs. The phenotype in the sibs resembles acrocallosal syndrome but differs in absence of macrocephaly, underdeveloped callosal body, and post-axial polydactyly. The patients also resemble Greig cephalopolysyndactyly syndrome but the absence of macrocephaly, broad thumbs, polydactyly, affected sibs and parents make this diagnosis unlikely. Classical cytogenetic and array CGH failed to show an abnormality. The sibs may have a hitherto undescribed entity, possibly with an autosomal recessive pattern of inheritance.