A Nine-Month-Old Boy With Isodicentric Chromosome 15: A Case Report
A 9-month-old boy visited our clinic with development. He was born at term by normal delivery with birth weight of 3.7 kg after an uneventful pregnancy. The family history was non-contributory. There were no notable prenatal and immediately postnatal problems. He had been taken to another clinic at four months because he could not hold his head. Brain magnetic resonance image scan, thyroid function test, and metabolic work ups were done at that time with normal results. At nine months old, he visited our clinic due to his persistent developmental problems. Minor craniofacial dysmorphism involving mildly deep-set eyes, downslanting palpebrae, microcephaly, and hypotonic face were observed (). On physical examination, there were no abnormal neurological signs such as persistent primitive reflex, ankle clonus, Babinski's sign or hyperactive deep tendon reflexes. Diffuse hypotonia was noted. He could hold his head at six months and sat with support at nine months, but he could not sit without support nor crawl reciprocally at that time. He could reach with his arm to get a toy with palmar grasp. He was babbling and attentive during play, also was able to share enjoyment, to pleasure with other people, and to make eye to eye contact. Stereotyped movements such as repetitive hand twisting or head turning and hand wringing were not observed. He had a Mental Developmental Index (MDI) score of 74 and a Psychomotor Developmental Index (PDI) score of 51 on Bayley Scales of Infant Development II tests and a social intelligence quotient (SQ) of 79.3 on the social maturity scale. His subcategorical development was estimated at four to five months in the cognitive area, four months in the language and motor areas, and six months in the social areas. On chromosomal study, chromosomal abnormality of 47,XY,+idic(15)(q12) was identified (). Chromosomal analysis for his parents was strongly recommended but this was refused. He had physical and occupational therapy in order to reduce his developmental delay. He sat without support at 11 months, could crawl at 13 months, came to walk along the furniture at 17 months, and stood alone for a few seconds at 19 months. Psychological evaluation at this point showed scores below 50 on both the MDI and PDI of the Bayley scale and the SQ of 68.3 for social maturity. His overall developmental lags were seven months in the social and language areas, and eight to nine months in other areas. On the Childhood Autism Rating Scale (CARS), his score was 15 and he did not show any distinctive autism or autistic like behavior. At 19 months he had no history of clinically notable seizure and his electroencephalography (EEG) findings were normal.