Key words cerebrospinal fluid, DMD, middle chain fatty acid, mental retardation.We report on a male child with Duchenne muscular dystrophy (DMD) accompanied by a chromosomal anomaly, who showed serious developmental delay and anomalies. His clinical features were not typical of DMD and the levels of middle chain fatty acid in his cerebrospinal fluid were high. Informed consent for this report was obtained from the parents.
CaseA 2-month-old boy was admitted because of fever and rash and was treated under the diagnosis of Kawasaki disease. At that time a developmental delay (he was unable to smile or follow moving targets) and hypotonia was found. His uncle showed hypotonia at birth, was diagnosed with DMD and died at the age of 20 of respiratory failure due to aspiration pneumonia. The presented patient was born as appropriate for date (his weight was 2156 g at 35 weeks) and kept in incubator because of apnea. His Apgar score was 9, and Guthrie test results were normal. On admission his height and weight were 55 cm (+0.44 SD) and 4320 g (+0.03 SD), respectively. He had brachycephalus, a high arched palate and left earlobe groove (Fig. 1). He showed general proximal muscle weakness and passive dorsiflexion could be seen on his knee, hands, elbows and foot joints. There was neither muscle atrophy nor pseudohypertrophy (enlargement of calf muscles). He showed horizontal nystagmus, frog leg position and positive Scarf sign. He was unable to smile or follow moving targets, he showed difficulty with head control and blood examination revealed increased muscle enzymes of aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH), creatine kinase (CK), aldolase (ALD) (AST 239 IU/L, ALT 255 IU/L, LDH 1096 IU/L, CK 21747 IU/L (maximum 37919), ALD 263 IU/L). Thyroid function tests were normal. All hepatotropic viral studies were negative. Cell count, protein and pressure of cerebrospinal fluid, as well as metabolic studies (amino acid and organic acid), were all normal. Lactate and pyruvate were 15.5 mg/dL and 0.89 mg/dL, respectively in cerebrospinal fluid. There was no metabolic acidosis. AST, ALT, LDH, CK and ALD were constantly high until the age of 2. Chromosome analysis by G-Banding (Fig. 2) showed 46Y,inv(X)(p21.2q22.3). Multiplex ligation probe amplification analysis using 19 exons (Pm,3,4,6,8,12,13, 17, 19, 43, 44, 45, 46, 47, 48, 50, 51,52, 60) revealed a deletion, expanding from exon 42 to 60 (79) in DMD. Muscle biopsy at the age of 2 years showed scattered necrotic and regenerating fibers with moderate endomysial fibrosis, in addition to a moderate variation in fiber size. Immunohistochemical analysis revealed an absence of dystrophin, confirming the diagnosis of DMD (Fig. 3). Magnetic resonance imaging was normal except for mild atrophy in the frontal and parietal region. The progress of atrophy is not shown. Awake electroencephalogram at the age of 2 showed no epileptic discharge or a wave in the occipital area. Computed tomography showed a low density area in the muscle of...
