Growth retardation-alopecia-pseudoanodontia-optic atrophy (GAPO) syndrome is a form of ectodermal dysplasia, one of a group of syndromes deriving from abnormalities of the ectodermal structures, which include the hair, teeth, nails, sweat glands, cranial-facial structure, and hands. These syndromes are genetic disorders that can be inherited, or passed down among family members, in an autosomal dominant or recessive manner. GAPO syndrome is hypothesized to be autosomal recessive, based on parental consanguinity (parents who are genetically related) and case reports of affected siblings.
The GAPO phenotype is characteristically progressive in nature and may be attributed to the accumulation of extracellular connective tissue matrix.
Symptoms of GAPO affect the hair, teeth, eyes, skin, and face. Specifically, GAPO syndrome is characterized by reduced birth length, alopecia (hair loss from the scalp or body), failure of the teeth to erupt from the gums, and loss of some or all of the fibers of the optic nerve, a condition known as optic atrophy. The optic nerve carries visual information from the eye to the occipital lobe in the brain, which then processes the information. In addition, physical growth is delayed. Symptoms such as reduced birth length can be observed at birth.
GAPO syndrome is a rare, inherited genetic disorder. Scientists first described the syndrome in 1947, since which time there has been the suggestion of a potential founder effect.
The genetic mutation or defect that causes GAPO syndrome is located on one of the 22 pairs of autosomes. Because it is a recessive disorder, two copies of the defective gene, one from each parent, are necessary for the disease to appear. GAPO syndrome is extremely rare, with fewer than 30 known cases in the scientific literature. Its exact incidence is unknown, but parents who are consanguineous are more likely to have a child with GAPO syndrome. GAPO syndrome appears to affect males and females and all racial and ethnic groups equally.
The life expectancy of people with GAPO syndrome may be reduced. In a report of adults with GAPO syndrome who died in their 30s or 40s, heart disease and other tissue changes were observed. The cause of this heart disease and tissue change is yet unknown. People with GAPO syndrome are generally of normal intelligence.
There is no cure for GAPO syndrome. Instead, treatment aims to reduce symptoms and prevent or treat complications.
Alopecia, anodontia, ectodermal dysplasia, eye defects, GAPO, growth retardation, inherited genetic condition, optic atrophy.