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A syndrome in which parts of both ends of chromosome 13 have been lost (deletion) and the two broken ends reunited to form a ring-shaped figure. Phenotypic expression varies according to breakpoint locations and lengths of deleted segments. Some patients exhibit only minor dysmorphic features but most are severely affected by a wide range of abnormalities. The clinical picture in many cases is similar to that seen in terminal deletions of the long arm of chromosome 13 and includes retinoblastoma, mental and growth retardation, brain malformations, heart defects, distal limb deformities, and digestive, urogenital, and other abnormalities, and some cases of ring chromosome 13 share many common characteristics with the Garcia-Lurie syndrome, including aprosencephaly, atelencephaly, microcephaly, craniofacial dysproportion, urogenital anomalies, adrenal hypoplasia, digital abnormalities, and severe retardation.
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