GAPO Syndrome: A Report of Two Siblings and a Review of Literature Arti Nanda, M.D., D.N.B.E.,* Wafa A. Al-Ateeqi, F.R.C.P.C.H., M.R.C.P.C.H.,  Mona A. Al-Khawari, M.R.C.P., F.R.C.P.C.H., Qasem A. Alsaleh, M.D.,* and Jeoram T. Anim, F.R.C.Path.   *As’ad Al-Hamad Dermatology Center, Al-Sabah Hospital,  Department of Pediatrics, Al-Amiri Hospital, and   Department of Pathology, Faculty of Medicine, Kuwait University, Kuwait Abstract: Growth retardation, alopecia, pseudoanodontia, optic atro- phy (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, histo- logic, and ultrastructural features in two siblings born to consanguineous parents with a brief review of the literature. Growth retardation, alopecia, pseudoanodontia, optic atrophy (GAPO) syndrome (OMIM *230740), as the acronym implies, refers to growth retardation (G); alopecia (A); pseudoanodontia (P); and optic atrophy (O). The condition was first described by Anderson and Pinborg in 1947 (1), but the acronym GAPO was coined by Tripton and Gorlin in 1984 (2). It is a rare condition and approximately 30 patients with GAPO syndrome have been reported in the literature (1–25). An autosomal recessive mode of inheritance has been suggested in several reports. The patients have a peculiar geriatric look and because of this many patients with GAPO syndrome can be diagnosed in early infancy. A basic underlying molecular defect in GAPO syndrome is yet to be defined as the candidate gene is still unknown. We report two additional patients (siblings) with GAPO syndrome and review the literature on this rare disorder. CASE REPORTS Patient 1 A 6-year-old Pakistani male child, first of two siblings, born to consanguineous (first cousins once removed) healthy parents, was delivered at term by a normal vaginal delivery and had a birthweight of 3,700 g. He was noticed to have dysmorphic facial features at birth and a progressive loss of hair from the scalp, eyebrows, and eyelashes since early infancy. His psychomotor development was satisfactory but was noticed to have a stunted growth and a failure of primary teeth to erupt. He had normal sweating and was without a history of any other associated medical ailment. Family history was positive for similar disease in younger female sibling. Mother had two abortions, each at 2nd month of gestation, of unknown cause. On examination, his weight was at the 10th and height below the 3rd percentile. He was observed to have frontal Address correspondence to Arti Nanda, M.D., D.N.B.E., PO Box 6759, Salmiya, 22078, Salmiya, Kuwait, e-mail: artinanda@ hotmail.com. DOI: 10.1111/j.1525-1470.2010.01100.x 156 Ó 2010 Wiley Periodicals, Inc. CASE REPORTS Pediatric Dermatology Vol. 27 No. 2 156–161, 2010