A novel heterozygous missense mutation G316D of SIX3 gene in a Brazilian patient with holoprosencephaly-like phenotype and Langerhans cell histiocytosis.

Here we report on a Brazilian female patient with the clinical manifestations of the holoprosencephaly-like phenotype who also presented with a retroocular granuloma diagnosed as Langerhans cell histiocytosis in early infancy. Mutation analysis showed a missense mutation (G316D) in the exon 2 of SIX3 gene, which was predicted as damaged by the PolyPhen program. We discuss the clinical and genetic aspects of this unusual case.

Holoprosencephaly, ectrodactyly, and bilateral cleft of lip and palate: exclusion of SHH, TGIF, SIX3, GLI2, TP73L, and DHCR7 as candidate genes.

We describe a Brazilian boy with semilobar holoprosencephaly, ectrodactyly, bilateral cleft of lip and palate, and severe mental retardation. The karyotype was normal and the screening for mutations in the genes SHH, TGIF, SIX3, GLI2, TP73L, and DHCR7 did not show any change. This rare condition was described previously in seven male patients.

Sonic hedgehog (SHH) mutation in patients within the spectrum of holoprosencephaly.

Holoprosencephaly (HPE) is a malformation sequence where the cerebral hemispheres fail to separate into distinct left and right halves. It can be associated with midline structural anomalies of the central nervous system and/or face. SHH is the major gene implicated in HPE and it plays a critical role in early forebrain and central nervous system development.