Biemond Syndrome II

Clinical Characteristics
Ocular Features: 

This disorder may belong to the spectrum of Bardet-Biedl syndromes (209900) but is listed separately because of the prominent association of iris colobomata.  Retinal dystrophy resembling retinitis pigmentosa is also part of this disorder but the rarity of cases precludes a full description of the phenotype.

Systemic Features: 

Underdevelopment of the external genitalia is more prominent in males.  Obesity, hydrocephalus and mental retardation are also features.  Postaxial polydactyly is common.  Renal disease does not seem to be part of this disorder.


Little is known about the inheritance or genetic defect responsible.  Colobomas and polydactyly have been found in relatives of patients with Biemond syndrome suggesting that this may be an autosomal dominant disorder with variable penetrance.

Treatment Options: 

None known.

Article Title: 


Verloes A, Temple IK, Bonnet S, Bottani A. Coloboma, mental retardation, hypogonadism, and obesity: critical review of the so-called Biemond syndrome type 2, updated nosology, and delineation of three "new" syndromes. Am J Med Genet. 1997 Apr 14;69(4):370-9.

PubMedID: 9098485