Background: 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.
Method: Clinical and cytogenetic investigations were carried out in an adult female with microcephaly and intellectual disability.
Results: 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.
Conclusion: The mosaicism for a chromosomal anomaly is an under-recognised cause of intellectual disability.