Ring chromosome 22: a review of the literature and first report from India.

Ring chromosome 22 [r(22)], a rare cytogenetic finding, has been described in nearly 70 cases to date. Cytogenetic investigations were carried out on a 5-year-old male child with microcephaly and intellectual disability. Cytogenetic investigations revealed his karyotype to be 46,XY,r(22). To the best of our knowledge, this is the first report of an r(22) anomaly from India.