Unusual Turner Syndrome Mosaic with a Triple X Cell Line (47,X/49,XXX) in a Western Lowland Gorilla (Gorilla gorilla gorilla)
A 29-yr-old female Western Lowland gorilla (Gorilla gorilla gorilla) was evaluated for low fertility and a mid-term abortion. Laboratory testing included karyotyping, which revealed an unusual mosaicism for Turner syndrome with Triple X (47X/49XXX). This appears to be the first report of Turner syndrome in a great ape. In humans, Turner syndrome occurs in approximately 1/3000 females, with half of those monosomic for the X chromosome. A small proportion is mosaic for a triple X cell line (3–4%).2 In humans, Turner Syndrome is associated with characteristic phenotype including short stature, obesity, a broad chest with widely spaced nipples, webbing of the neck, and anteverted ears.1 This individual gorilla is significantly shorter in stature than conspecifics and is obese despite normal caloric intake. Individuals with Turner syndrome should also be screened for common health issues including congenital heart defects, obesity, kidney abnormalities, hypertension, hypothyroidism, and diabetes mellitus. Animals with decreased fertility, multiple miscarriages, fetal losses, and/or unusual phenotypes should be evaluated for genetic abnormalities.
The authors thank Marlys Houck, CLSp (GC) from the San Diego Institute for Conservation Research for consultation regarding this case, Melanie Meyer from Pinon Perinatal for editing assistance, and the ape keepers at the Rio Grande Zoo for their excellent care of the gorillas.
1. Morgan, T. 2007. Turner syndrome: diagnosis and management. American Family Physician. 76:405–417.
2. Sybert, V.P. 2002. Phenotypic effects of mosaicism for a 47,XXX cell line in Turner syndrome. J. Med. Genet. 39:217–221.