Anterior Segment Dysgenesis 6

Clinical Characteristics
Ocular Features: 

This is a congenital anterior segment dysplasia syndrome.  Iris hypoplasia with transillumination, corectopia, iridodenesis, and iridocorneal adhesions can be seen.  Increased intraocular pressure is a risk and ectopia lentis is often present.  Peters anomaly and defects in all layers of the cornea may be present.

No foveal hypoplasia is present.

Systemic Features: 

No systemic abnormalities have been reported.

Genetics

A single male patient of native American/French Canadian background has been reported with compound heterozygous mutations in the CYP1B1 gene (2p22.2).

See Anterior Chamber Dysgenesis 8 for another autosomal recessive disorder with somewhat similar clinical features.  Three families with 4 affected individuals have been reported with homozygous or compound heterozygous mutations in the CPAMD8 gene (19p13.11).

The genes FOXE3 and PAX6 are characterized as transcription factors and play important roles in ocular development.  However, while mutations in these are frequently found in patients with dysgenesis of the anterior chamber they often cause more widespread ocular and systemic anomalies (e.g., Gillespie syndrome [206700]).  Therefore in this database the anterior chamber constellations of anomalies associated with mutations in these genes are not considered to be simplex conditions.

See also related disorders iridogoniodysgenesis type 1 (601631) and type 2 (137600), and anterior segment mesenchymal dysgenesis (107250).

Treatment
Treatment Options: 

Lifelong pressure monitoring is important.

References
Article Title: 

Phenotypic heterogeneity of CYP1B1: mutations in a patient with Peters' anomaly

Vincent A, Billingsley G, Priston M, Williams-Lyn D, Sutherland J, Glaser T, Oliver E, Walter MA, Heathcote G, Levin A, Heon E. Phenotypic heterogeneity of CYP1B1: mutations in a patient with Peters' anomaly. J Med Genet. 2001 May;38(5):324-6. PubMed PMID: 11403040; PubMed Central PMCID: PMC1734880.

PubMed ID: 
11403040

References

Cheong SS, Hentschel L, Davidson AE, Gerrelli D, Davie R, Rizzo R, Pontikos N, Plagnol V, Moore AT, Sowden JC, Michaelides M, Snead M, Tuft SJ, Hardcastle AJ. Mutations in CPAMD8 Cause a Unique Form of Autosomal-Recessive Anterior Segment Dysgenesis. Am J Hum Genet. 2016 Dec 1;99(6):1338-1352.

PubMedID: 27839872

Vincent A, Billingsley G, Priston M, Williams-Lyn D, Sutherland J, Glaser T, Oliver E, Walter MA, Heathcote G, Levin A, Heon E. Phenotypic heterogeneity of CYP1B1: mutations in a patient with Peters' anomaly. J Med Genet. 2001 May;38(5):324-6. PubMed PMID: 11403040; PubMed Central PMCID: PMC1734880.

PubMedID: 11403040