Growth retardation, alopecia, pseudoanodontia, and optic atrophy (GAPO syndrome) with congenital glaucoma

Genetic Spectrum and Characteristics of Hereditary Optic Neuropathy in Taiwan

Hereditary optic neuropathy (HON) is a group of genetically heterogeneous diseases that cause optic nerve atrophy and lead to substantial visual impairment. HON may present with optic nerve atrophy only or in association with various systemic abnormalities. Although a genetic survey is indispensable for diagnosing HON, conventional sequencing techniques could render its diagnosis challenging. In this study, we attempted to explore the genetic background of patients with HON in Taiwan through capture-based next-generation sequencing targeting 52 HON-related genes. In total, 57 patients from 48 families were recruited, with 6 patients diagnosed as having Leber hereditary optic neuropathy through initial screening for three common variants (m.3460G>A, m.11778G>A, m.14484T>C). Disease-causing genotypes were identified in 14 (33.3%) probands, and OPA1 variants were the most prevalent cause of autosomal HON. Exposure to medications such as ethambutol could trigger an attack of autosomal dominant optic atrophy. WFS1 variants were identified in three probands with variable clinical features in our cohort. Hearing impairment could occur in patients with OPA1 or WFS1 variants. This is the first comprehensive study investigating the genetic characteristics of HON in Taiwan, especially for autosomal HON. Our results could provide useful information for clinical diagnosis and genetic counseling in this field.

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

This article reports on the ophthalmological features of four Turkish children with GAPO syndrome, a very rare autosomal recessive condition characterized by growth retardation (G), alopecia (A), pseudoanodontia (P) (failure of tooth eruption), and optic atrophy (O). The children were from two unrelated families born to consanguineous parents. They had the characteristic facial appearance of alopecia, rarefaction of eyebrows and eyelashes, frontal bossing, high forehead, midfacial hypoplasia, hypertelorism, and thickened eyelids and lips. Two children had severe end-stage glaucoma in both eyes and unilateral corneal opacity, whereas other two children had myelinated retinal nerve fiber layer; one with bilateral optic atrophy and the other one with persistent pupillary membrane in the left eye.

GAPO syndrome: a report of two siblings and a review of literature

Growth retardation, alopecia, pseudoanodontia, optic atrophy (GAPO) syndrome is a rare autosomal recessive disorder. The molecular nature of the disease is not fully understood and is considered to be one of the ectodermal dysplasia defects. In this report, we describe clinical, histologic, and ultrastructural features in two siblings born to consanguineous parents with a brief review of the literature.

Ophthalmic Aspects of GAPO Syndrome: Case Report and Review

This paper reports on a 36-year-old woman with GAPO syndrome, a rare autosomal recessive condition characterized by growth retardation (G), alopecia (A), pseudoanodontia (P), and optic atrophy (O). Her parents are consanguineous and one of her sisters is also affected. Since the first description by Anderson and Pindborg in 1947, 27 individuals have been reported with this diagnosis. They were from at least 19 different families (four of them from Brazil, including the present one), suggesting a founder effect. The phenotype of this condition, initially considered as the result of an ectodermal dysplasia, could be attributed to the accumulation of extracellular connective tissue matrix and its progressive character must be pointed out. The clinical findings, especially ophthalmological features that include bilateral glaucoma, are reviewed and discussed.

GAPO syndrome: three new Brazilian cases, additional osseous manifestations, and review of the literature

The GAPO syndrome is an extremely rare autosomal recessive disease that presents as main characteristics evident growth retardation, alopecia, pseudoanodontia, progressive optic atrophy and a typical face. Until now, only 30 patients have been reported in the medical literature (nine of them from Brazil, including the three cases described in the present article). This study describes three siblings with GAPO syndrome, two female and one male, the children of consanguineous parents (first-degree cousins, inbreeding F = 1/16), who are older than the previously described patients, presenting the characteristic phenotype besides serious bone alterations in the lower limbs, which had not yet been observed.