MedGen

Hydrolethalus syndrome is an autosomal recessive embryonic lethal disorder characterized by hydrocephaly or anencephaly, postaxial polydactyly of the upper limbs, and pre- or postaxial polydactyly of the lower limbs. Duplication of the hallux is a common finding. HLS2 is considered a ciliopathy (summary by Putoux et al., 2011). Acrocallosal syndrome (ACLS; 200990) is an allelic disorder with a less severe phenotype. For a discussion of genetic heterogeneity of hydrolethalus syndrome, see 236680. [from OMIM]

Al-Gazali-Bakalinova syndrome (AGBK) is characterized by multiple epiphyseal dysplasia, macrocephaly, and distinctive facial features including frontal bossing, hypertelorism, flat malar regions, low-set ears, and short neck. Other features include pectus excavatum, spindle-shaped fingers, clinodactyly, prominent joints, and genu valgum (summary by Ali et al., 2012). [from OMIM]

Classic Joubert syndrome (JS) is characterized by three primary findings: A distinctive cerebellar and brain stem malformation called the molar tooth sign (MTS). Hypotonia. Developmental delays. Often these findings are accompanied by episodic tachypnea or apnea and/or atypical eye movements. In general, the breathing abnormalities improve with age, truncal ataxia develops over time, and acquisition of gross motor milestones is delayed. Cognitive abilities are variable, ranging from severe intellectual disability to normal. Additional findings can include retinal dystrophy, renal disease, ocular colobomas, occipital encephalocele, hepatic fibrosis, polydactyly, oral hamartomas, and endocrine abnormalities. Both intra- and interfamilial variation are seen. [from GeneReviews]