Cystic fibrosis and Russell-Silver syndrome in a child with maternal isodisomy of chromosome 7.

A 6-year-old Asian girl was diagnosed with cystic fibrosis at 3 months of age, following investigations for failure to thrive. She had intrauterine growth retardation and continued to have restricted postnatal growth, despite adequate caloric intake and enzyme replacement therapy. Further investigations were initiated when she was 5 years old, as her growth was not responding to the usual treatment measures. These tests revealed that she had maternal isodisomy of chromosome 7.