Case 1: A Hypotonic Newborn

Abstract

The patient is a full-term male infant and fourth child of nonconsanguinous parents. He was conceived naturally and his mother was well throughout the pregnancy. An amniocentesis performed at 17 weeks’ gestation showed normal chromosomes: 46,XY. Late-onset growth restriction occurred from 32 weeks of gestation and was symmetrical, with all parameters at the 10th percentile. No fetal anomalies were detected in antenatal scans. The infant was delivered vaginally at 38 weeks’ gestation. He was vigorous at birth with good Apgar scores and a birthweight of 2.365 kg. At 4 hours, the infant was reported to be hypotonic, lethargic, and sucking poorly. He was quiet and had a weak cry, with minimal grimacing to painful stimulus. He had limited peripheral movements, both proximal and distal, with frog leg posturing of his lower limbs and marked head lag. His muscle bulk was preserved and no muscle fasciculations were seen. Deep tendon reflexes were normal. He had a poor suck and rooting reflex. His pupils were normal and reactive …