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Updated: Oct 28, 2026
Assessment and Evaluation of the High Risk Neonate: The NICU Network Neurobehavioral Scale
Published on: August 25, 2014
Neonatal nemaline myopathy associated with NEB variants and a favorable 3-year outcome: A case report
Zhengxi Liu1, Ya Luo2, Guiping Li1
1Department of Neonatology, Children's Diagnosis and Treatment Center, The Affiliated Traditional Chinese Medicine Hospital, Southwest Medical University, Luzhou, Sichuan, China.
Rationale:
Nemaline myopathy (NM) is a rare congenital myopathy characterized by muscle weakness and hypotonia. Severe neonatal disease may involve respiratory failure and bulbar dysfunction. Variants in the nebulin gene (NEB) are a common genetic cause, but genotype-phenotype relationships and prognosis remain variable.
Patient Concerns:
A female neonate developed cyanosis, bradycardia, respiratory distress, and hypotonia shortly after birth. She required invasive mechanical ventilation and later experienced recurrent respiratory deterioration, difficulty weaning from ventilatory support, poor feeding, vomiting and choking, weak sucking and swallowing, and diminished primitive reflexes.
Diagnoses:
The clinical phenotype and trio whole-exome sequencing findings supported a clinical diagnosis of NM associated with NEB variants. Sequencing identified a maternally inherited pathogenic frameshift variant, c.23910_23911delAG (p.Arg7970SerfsTer9), and 2 missense variants classified as variants of uncertain significance: maternally inherited c.5615C>T (p.Pro1872Leu) and paternally inherited c.19550G>A (p.Arg6517His). Muscle biopsy, allelic phasing, and functional studies were unavailable; therefore, the molecular diagnosis was not definitive.
Interventions:
The patient received invasive and noninvasive respiratory support, oxygen therapy, feeding and symptomatic management, serial neurological assessments, and neurological rehabilitation.
Outcomes:
The Neonatal Behavioral Neurological Assessment score increased from 25 on day 7 to 30 on day 14 and 36 on day 28. Respiratory function, feeding, and muscle tone gradually improved, allowing respiratory support to be withdrawn. Denver Developmental Screening Test assessments performed at 6-month intervals after discharge identified no reported developmental abnormalities. At 3 years of age, no apparent hypotonia, movement disorder, or other clinically evident motor impairment was observed.
Lessons:
Neonatal NM associated with NEB variants may present with life-threatening respiratory and bulbar dysfunction yet be followed by a favorable early developmental course. Trio whole-exome sequencing may facilitate etiological evaluation, but NEB variants require cautious interpretation when histopathological, phasing, and functional evidence is unavailable. A severe neonatal presentation should not be regarded as indicating an invariably poor prognosis, and continued neuromuscular, respiratory, feeding, orthopedic, and developmental surveillance remains warranted.
