Compound heterozygous RYR1 mutations in a preterm with arthrogryposis multiplex congenita and prenatal CNS bleeding.

RYR1 mutations, the most common cause of non-dystrophic neuromuscular disorders, are associated with the malignant hyperthermia susceptibility (MHS) trait as well as congenital myopathies with widely variable clinical and histopathological manifestations. Recently, bleeding anomalies have been reported in association with certain RYR1 mutations. Here we report a preterm infant born at 32 weeks gestation with arthrogryposis multiplex congenita due to compound heterozygous, previously MHS-associated RYR1 mutations, with additional signs of prenatal hemorrhage. The patient presented at birth with multiple joint contractures, scoliosis, severe thoracic rigidity and respiratory failure. He continued to depend on mechanical ventilation and tube feeding. Muscle histopathology showed a marked myopathic pattern with eccentric cores. Interestingly, the patient had additional unusual prenatal intraventricular hemorrhage, resulting in post-hemorrhagic hydrocephalus as well as epidural hemorrhage affecting the spinal cord. This report adds to the phenotypic variability associated with RYR1 mutations, and highlights possible bleeding complications in affected individuals.