GAPO syndrome: report on the first case in Japan

Two siblings with GAPO syndrome: Ophthalmic presentation and histopathologic findings

BACKGROUND

GAPO syndrome (growth retardation, alopecia, pseudoanodontia, optic atrophy) is a rare, autosomal recessive connective tissue disorder with only 60 reported cases. Ophthalmic manifestations vary and include hypertelorism, optic atrophy, and glaucoma. There have been three reported cases of GAPO syndrome with craniosynostosis.

MATERIALS/METHODS

We describe two new siblings with GAPO syndrome and craniosynostosis and the first histopathologic analysis of Tenon's capsule and extraocular muscle in this syndrome.

RESULTS

Both siblings presented with papilledema and V-pattern strabismus in addition to the alopecia, brittle eyelashes, growth retardation, and pseudoanodontia that characterize GAPO syndrome. Cranial vault expansion, though successful, was complicated by lack of distinct periosteal layers, thin dural adherence to bone, and extensive venous bleeding. Tenons encountered during strabismus surgery was inelastic and highly vascular. Histopathological analysis revealed hyalinization of Tenon's and a thickened, homogenized, amorphous appearance, similar to the extracellular matrix abnormalities described in skin and other organs Histopathological analysis of extraocular muscle was, in contrast, unremarkable.

CONCLUSIONS

GAPO impacts the extracellular matrix of Tenon's resulting in inelasticity and hypervascularity. Ophthalmologists should be mindful of these aberrant characteristics when planning surgery in this population.

GAPO syndrome with craniosynostosis and intracranial hypertension

BACKGROUND

GAPO (growth retardation, alopecia, pseudoanodontia, and optic atrophy) as a rare genetic disorder includes growth retardation, alopecia, pseudoanodontia, and optic atrophy. It was reported to be associated with craniosynostosis and intracranial hypertension.

CASE REPORT

A patient with such a rare disorder associated with multisuture craniosynostosis and headache is presented. Surgery has been done due to intracranial hypertension.

CONCLUSIONS

Abnormal intraoperative findings including sever pericranium and dural adhesions and extraordinary bleeding related to this syndrome are described.

GAPO syndrome in seven new patients: Identification of five novel ANTXR1 mutations including the first large intragenic deletion

GAPO syndrome is a very rare disorder characterized by growth retardation, alopecia, pseudoanodontia and progressive optic atrophy. It is caused by biallelic mutations in the ANTXR1 gene. Herein, we describe the clinical and molecular findings of seven new patients with GAPO syndrome. Our patients presented with the characteristic clinical features of the syndrome except for one patient who did not display total alopecia till the age of two years. Strikingly, optic atrophy and glaucoma were observed in all patients and one patient showed keratopathy in addition. Moreover, craniosynstosis was an unusual associated finding in one patient. Mutational analysis of ANTXR1 gene identified five novel homozygous mutations including two frameshift, two splice site and a large intragenic deletion of exon 3. Our results reinforce the clinical characteristics of the syndrome, expand the mutational spectrum and provide more insights into the role of the ANTXR1 protein in the regulation of extracellular matrix.

Whole exome sequencing identifies three novel mutations in ANTXR1 in families with GAPO syndrome

GAPO syndrome (OMIM#230740) is the acronym for growth retardation, alopecia, pseudoanodontia, and optic atrophy. About 35 cases have been reported, making it among one of the rarest recessive conditions. Distinctive craniofacial features including alopecia, rarefaction of eyebrows and eyelashes, frontal bossing, high forehead, mid-facial hypoplasia, hypertelorism, and thickened eyelids and lips make GAPO syndrome a clinically recognizable phenotype. While this genomic study was in progress mutations in ANTXR1 were reported to cause GAPO syndrome. In our study we performed whole exome sequencing (WES) for five affected individuals from three Turkish kindreds segregating the GAPO trait. Exome sequencing analysis identified three novel homozygous mutations including; one frame-shift (c.1220_1221insT; p.Ala408Cysfs*2), one splice site (c.411A>G; p.Gln137Gln), and one non-synonymous (c.1150G>A; p.Gly384Ser) mutation in the ANTXR1 gene. Our studies expand the allelic spectrum in this rare condition and potentially provide insight into the role of ANTXR1 in the regulation of the extracellular matrix.

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.

GAPO syndrome: first Egyptian case with ultrastructural changes in the gingiva

We report on a 3-year-old boy with growth retardation, alopecia, pseudoanodontia, and optic atrophy. This is the 18th known and the first Egyptian case of GAPO syndrome. Electron microscopic examination of gingival biopsy showed excessive collagen fibres and endothelial vacuolisation, suggesting involvement of extracellular pathological collagenosis.