OBJECTIVETo study the level of intelligence in children with Duchenne muscular dystrophy (DMD), and the relationship between the level of intelligence and gene mutations.

METHODSOne hundred and two children with DMD between January 2009 and March 2011 were enrolled. DMD gene detection was performed through the multiplex ligation-dependent probe amplification (MLPA) in 84 cases. The level and the structure of intelligence were evaluated by Chinese Wechsler Intelligence Scale for Children (C-WISC) in 50 children with DMD (≥6 years old; DMD group) and in 50 age-and gender-matched healthy children (control group).

RESULTSThe average intelligence quotient (IQ) was 84±21 in 102 children with DMD. Thirty patients (29.4%) had the full intelligence quotient (FIQ) less than 70. The FIQ, verbal intelligence quotient (VIQ), performance intelligence quotient (PIQ) and the scores of 11 sub-tests of intelligence in the DMD group were significantly lower than those in the control group (P<0.01). The IQ in patients with gene mutations at exon 56-79 was the lowest (59.3±11.9), followed by in patients with gene mutations at exon 45-55 (88.6±1.9), at exon 1-29 (97.5±9.6) and at exon 30-44 (102.8±3.8) (P<0.01).

CONCLUSIONSThe FIQ, VIQ and PIQ in children with DMD are lower than those in healthy children. There is association between mental retardation and gene mutations.