Antenatal-Onset Clues to Congenital Myopathy in a Term Neonate With Birth Asphyxia: A Case Report

Hypoxic-ischemic encephalopathy (HIE) readily explains hypotonia, seizures, and respiratory failure in a term neonate who is depressed at birth, so a coexisting congenital myopathy may go unrecognized.We describe a term female neonate born after reduced fetal movements and meconium-stained liquor, with Apgar scores of 3 and 6 at one and five minutes, who was assessed as having stage II HIE; therapeutic hypothermia was unavailable.From the first day of life, she also had contractures of both elbows and knees, bilateral pes cavus, areflexia, and facial and bulbar weakness.An elder sister had died on the sixth day of life of an undetermined cause.Total creatine kinase was not elevated (30 U/L).Weakness did not improve as expected for moderate encephalopathy, and extubation failed seven times because of inadequate respiratory effort, often with a clear chest radiograph.Over 65 days, she developed refractory shock, recurrent seizures, and eight cardiac arrests, and she died.Whole-exome sequencing, reported two days after her death, identified a homozygous in-frame deletion of uncertain significance in ryanodine receptor 1 (RYR1) and a homozygous OGDH variant of uncertain significance; tandem mass spectrometry showed elevated verylong-chain species without a corresponding genetic finding.Parental segregation analysis, muscle biopsy, electromyography, electroencephalography, and magnetic resonance imaging were not feasible.Contractures and pes cavus present at birth, together with reduced fetal movements, indicate weakness that began before labor and cannot be attributed to the intrapartum event.With areflexia, failed extubation despite clear lungs, and a normal or low creatine kinase, these findings should prompt evaluation for congenital myopathy in an asphyxiated neonate.These clues are clinical and inexpensive, and they remain useful where confirmatory testing is slow or unavailable.