GAPO Syndrome

Clinical Characteristics

Ocular Features:

Progressive optic atrophy is considered part of this syndrome but it is not a consistent feature. One patient with the suspected diagnosis had papilledema while other individuals may have congenital glaucoma, buphthalmos, band keratopathy, and keratoconus. White eyelashes have been described. Myelinated nerve retinal nerve fibers may be prominent.

Systemic Features:

This is a rare congenital disorder with so far incomplete phenotypic delineation. The diagnosis can be made soon after birth from the general facial and body morphology. The dysmorphism is secondary to marked bone growth retardation and metaphyseal dysplasia, resulting in a flat midface, frontal bossing, micrognathism, chest deformities, and vertebral anomalies. Psychomotor retardation is common but the extent of cognitive deficits is unknown. The permanent teeth may begin to develop but fail to erupt (pseudoanodontia). Even primary dentition is often abnormal. Alopecia is a feature although some individuals do have sparse body hair, at least for a period of time. Anomalous blood vessels such as dilated scalp veins are sometimes evident. Hypogonadism has been reported in both sexes. Individuals are subject to recurrent ear and respiratory infections.

Genetics

GAPO occurs in both sexes. Homozygous mutations in the ANTXR1 [1] gene (2p13.3) are responsible for this disorder.

Treatment

Treatment Options:

Treatment is directed at individual problems. Prompt treatment of respiratory infections is important.

References

Article Title:

Mutations in ANTXR1 cause GAPO syndrome [2]

Stranecky V, Hoischen A, Hartmannova H, Zaki MS, Chaudhary A, Zudaire E, Noskova L, Baresova V, Pristoupilova A, Hodanova K, Sovova J, Hulkova H, Piherova L, Hehir-Kwa JY, de Silva D, Senanayake MP, Farrag S, Zeman J, Martasek P, Baxova A, Afifi HH, St Croix B, Brunner HG, Temtamy S, Kmoch S. Mutations in ANTXR1 cause GAPO syndrome. Am J Hum Genet. 2013 May 2;92(5):792-9.

PubMed ID:

23602711

GAPO syndrome: four new patients with congenital glaucoma and myelinated retinal nerve fiber layer [3]

Bozkurt B, Yildirim MS, Okka M, Bitirgen G. GAPO syndrome: four new patients with congenital glaucoma and myelinated retinal nerve fiber layer. Am J Med Genet A. 2013 Apr;161(4):829-34.

PubMed ID:

23494824

GAPO syndrome: a new case of this rare syndrome and a review of the relative importance of different phenotypic features in diagnosis [4]

Bacon W, Hall RK, Roset JP, Boukari A, Tenenbaum H, Walter B. GAPO syndrome: a new case of this rare syndrome and a review of the relative importance of different phenotypic features in diagnosis. J Craniofac Genet Dev Biol. 1999 Oct-Dec;19(4):189-200. Review.

PubMed ID:

10731088

Ophthalmic findings in GAPO syndrome [5]

Ilker SS, Ozturk F, Kurt E, Temel M, Gul D, Sayli BS. Ophthalmic findings in GAPO syndrome. Jpn J Ophthalmol. 1999 Jan-Feb;43(1):48-52.

PubMed ID:

10197743