boy with a submicroscopic 22qter deletion, general overgrowth and features suggestive of FG syndrome
De Vries B., Bitner‐Glindzicz M., Knight S., Tyson J., MacDermot K., Flint J., Malcolm S., Winter R.
Over recent years, submicroscopic subtelomeric rearrangements have been shown to be a significant cause of mental retardation and, therefore, such abnormalities should be considered in every child with moderate to severe retardation with additional features suggestive of a chromosomal abnormality. The FG syndrome is an X‐linked recessive mental retardation syndrome with congenital hypotonia, relative macrocephaly, a characteristic facies and constipation. We describe a severely mentally retarded boy with a history of severe constipation, truncal hypotonia, facial dysmorphism, fetal pads, and joint laxity, leading to an initial diagnosis of FG syndrome at the age of 3 years. Clinical re‐evaluation at the age of 6 years, when he showed signs of general overgrowth, initiated a telomere screen, and a submicroscopic 22q13.3 telomere deletion was detected. The features suggestive of FG syndrome in this boy with a 22q13.3→qter deletion may indicate testing for submicroscopic 22qter deletions in patients with atypical features of FG syndrome without a definite X‐linked family history.