We report on a 3 years old boy with severe mental retardation, hypotonia, deafness, cerebral dysmyelination, low levels of immunoglobulin A and dysmorphic features, bearing a distal deletion of 18q: 18q21-qter. Karyotype analysis by GTG banding was performed, revealing a deletion of the distal fragment of chromosome 18q, ranging from band q21 to qter, later confirmed by Fluorescence In Situ Hybridization (FISH). Whole chromosome painting for chromosome 18 ruled out any cryptic rearrangements involving other chromosomes. An attempted therapy with growth hormone did not bring any improvement and was discontinued due to an unexplained febrile episode and overall regress of the patient.
Keywords: 18q deletion; GH therapy; hypotonia.