Ring chromosome 7 in an Indian woman

Ring chromosome 7 [r(7)] is a rare cytogenetic aberration, with only 16 cases (including 3 females) reported in the literature to date. This is the first reported case of r(7) from India.

Clinical and cytogenetic investigations were carried out in an adult female with microcephaly and intellectual disability.

Ring chromosome 7 was observed in 10% of the metaphases (46,XX,r(7)/46,XX). The clinical findings revealed microcephaly, growth delay, and dark pigmented naevi.

The mosaicism for a chromosomal anomaly is an under-recognised cause of intellectual disability.