Concurrent prenatal diagnosis of hereditary neuropathy with liability to pressure palsies and congenital pulmonary airway malformation: A case report

RATIONALE: Hereditary neuropathy with liability to pressure palsies (HNPP) is a rare autosomal dominant peripheral neuropathy typically diagnosed in adolescence or adulthood. Prenatal diagnosis is exceedingly rare. Congenital pulmonary airway malformation (CPAM) is a common congenital lung lesion. We report a unique case of concurrent prenatal diagnoses of HNPP and CPAM, highlighting the importance of genetic evaluation when structural anomalies are detected prenatally. PATIENT CONCERNS: A 38-year-old pregnant woman (gravida 3, para 1) underwent a systematic prenatal ultrasound at 24 weeks of gestation, which revealed a hyperechoic lesion measuring approximately 49 mm × 27 mm × 39 mm in the fetal right thoracic cavity with blood supply from the right pulmonary artery. The pregnancy was otherwise uncomplicated. The fetus's father and paternal aunt had recurrent limb numbness and weakness, with a known genetic diagnosis of HNPP in the aunt. DIAGNOSES: Amniocentesis and chromosomal microarray analysis identified a 1.38 Mb heterozygous deletion at 17p12 encompassing the peripheral myelin protein 22 gene in the fetus, confirming the diagnosis of HNPP. The right-sided thoracic lesion was diagnosed as CPAM based on characteristic ultrasound features. INTERVENTIONS: Following multidisciplinary counseling, the parents opted to continue the pregnancy. Individualized perinatal planning was implemented, including elective cesarean delivery at 38 weeks to avoid instrumental extraction and minimize intrapartum nerve compression. Serial ultrasound follow-up was performed every 2 to 3 weeks, and a long-term neurological follow-up plan was established for the newborn. OUTCOMES: The patient delivered a healthy female neonate (3150 g, Apgar 9/10) via elective cesarean at 38 + 2 weeks. No neurological or respiratory deficits were observed. CPAM regressed gradually on follow‑up ultrasound. The infant is under regular pediatric and neurological surveillance, with chest imaging scheduled at 6 to 12 months. LESSONS: This case underscores the need for detailed family history and targeted genetic testing when prenatal ultrasound detects structural anomalies. For fetuses with HNPP, individualized perinatal planning - including elective cesarean and long‑term neurological follow‑up - is feasible and recommended. The co‑occurrence of HNPP and CPAM appears coincidental, with no causal link established.