[Genotype and phenotype analysis of neonates with neonatal encephalopathy complicated with perinatal hypoxic event]

Objective: To explore the underlying genetic causes of neonatal encephalopathy complicated with perinatal asphyxia. Methods: From the neonates recruited to the Neonatal Genome Project of Children's Hospital of Fudan University between January 2016 and January 2019, 113 neonates with neonatal encephalopathy and acute peripartum or intrapartum event or Apgar score ≤7 were enrolled in this study. The clinical data, laboratory results, the findings of electroencephalograph and magnetic resonance imaging or head ultrasound, and the genetic information were retrospectively analyzed. Results: Of the 133 neonates with neonatal encephalopathy and acute peripartum or intrapartum event or Apgar score ≤7 scores, 77 (57.9%) were males, 56 (42.1%) were female, 56 (42.1%) were delivered via cesarean section, and 77(57.9%) were born by vaginal delivery. Among these cases, 68 (51.1%) were diagnosed of hypoxic ischemic encephalopathy, 25 (18.8%) had intracranial hemorrhage, 20 (15%) were related to genetic diseases, and 5 (3.8%) had sepsis without central nervous infection. A total of 20 cases with positive results by next-generation sequencing test were identified, including 19 cases with pathogenic variations and 1 case with variation of uncertain significance. These 20 cases included 4 cases with congenital myopathy (2 cases of MTM1 gene pathogenic variants, 1 case of ACTA1 and 1 case of RYR1 gene pathogenic variants), 4 cases with genetic syndrome (2 cases of CHD7 gene pathogenic variants, 1 case of PTN11 gene pathogenic variant, and 1 case of NSDHL gene pathogenic variant), 3 cases with metabolic disorders (1 case of OTC gene pathogenic variant, 1 case of MTHFR gene pathogenic variant, and 1 case of ALDH7A1 gene pathogenic variant), 2 cases with epileptic encephalopathy (1 case of KCNT1 and 1 case of PACS2 gene pathogenic variants), 1 case with congenital central hypoventilation syndrome (PHOX2B gene pathogenic variant) and 6 cases with copy-number pathogenic variations. Among these 20 cases, 8(40.0%) neonates were presented with persistent hypotonia, 7(35.0%) neonates with seizures, and 5(25.0%) neonates with congenital malformation. Genetic counseling and further follow-up were performed or suggested for these 20 cases; 4 neonates were deceased, 10 neonates underwent palliative care, and 6 neonates were improved after supportive care and their further follow-up plan were performed in clinics. Conclusions: Genetic diseases are not rare in neonates with neonatal encephalopathy complicated with perinatal hypoxia event. The common causes in these neonates include congenital myopathy, metabolic disorders, genetic syndrome, and epilepsy encephalopathy.