Brain Stem Hypoplasia Associated with Cri-du-Chat Syndrome
A girl aged 1 year and 4 months was admitted for evaluation of psychomotor retardation and an operation for exotropia. She was born at term (gestational age: 40 weeks) by cesarean delivery after an uneventful pregnancy, and was the first child of healthy, unrelated parents. The family history was unremarkable. On admission, she was presented with a characteristic high-pitched cry and microcephaly. She showed delayed motor functions and crawling. She was able to sit unassisted but unable to stand; her developmental characteristics lagged behind for the normal chronologic age. On neurologic examination, she had left leg hypotonia, with normal tendon reflexes and normal cranial nerve signs.\nWhen she was 6 months old, the ventricular septal defect was detected by echocardiography. Chromosome analysis revealed 46,XX,del () (p15.2) one month after delivery, resulting in a diagnosis of 5p-syndrome. When the patient was 1-year-old, MRI revealed brain stem hypoplasia (most prominently in the pons), with normal cerebellum, diffuse mild atrophy of the deep white matter of both cerebral hemispheres, as well as mild thinning of the corpus callosum and mega cisterna magna. The anterior limb of the internal capsules on both sides showed reduced myelination, which decreased as compared to normal myelination patterns for 1-year-old infants ().