Background: The clinical features of ring chromo-some 14 and its possible relationship with severe growth retardation were studied.

Methods: Chromosome high-resolution G banding analysis on cultures at 550 band level of skin biopsy specimen and peripheral blood lymphocytes in patients with mental retardation at this hospital revealed a case of mosaicism of ring chromosome 14 (p11.2; q32.3), chromosome monosomy 14. The reported cases of ring 14 were analyzed.

Results: Ring chromosome 14 was detected in a 18-month-old female infant with severe growth retardation, seizure and minor abnormal craniofacial features including scaphocephaly and microcephalic, low-set ears, elongated face, short palpebral fissures, prominent nasal bridge, micrognathia, high palate, and short neck. Cells from skin fibroblasts showed that 50% cell line with 46, XX, r(14) and 50% with 45, XX, -14, had a 46, XX, r(14) (p11.2-q32.2)/45, XX, -14 karyotype.

Conclusions: Patients with ring 14 are characterized by mental retardation, seizures, microcephaly, low set ears, short palpebral fissure, depressed nasal bridge, shot neck, and retinal pigmentation. The seizure was a unique feature of ring chromosome 14; mental retardation, severe seizure, and abnormal facial features should be evaluated cytogenetically to rule out the appearance of ring chromosome 14. The amount of genetic material can be deleted from chromosome 14. The ring instability leading to aneusomy and the position effect of a telomere on ring chromosome determine the physical abnormalities and manifestations of ring chromosome 14. The structural and behavioral instability of a ring chromosome give rise to high proportion of secondary aneuploid, resulting in more severe growth retardation.