[Clinical analysis of heterozygous ABCA3 mutations in children]

To investigate the association of ATP-binding cassette transporter A3 (ABCA3) gene mutations with severe neonatal respiratory distress syndrome (NRDS) and lung disease in children.

Thirty-eight children hospitalized with respiratory disorders in Children's Hospital of Chongqing Medical University from January 2010 to December 2011 were screened. Two mutations (E292V, G1221S) in the ABCA3 gene were identified. Interstitial lung disease (ILD) was present in 10 cases, NRDS was found in 23 and congenital pulmonary dysplasia in 5 cases. There were 24 males and 14 females, with an age range of 1 hour to 15 years. Genomic DNA was prepared from blood samples and sequences were analyzed by polymerase chain reaction (PCR). Clinical feature, imaging characteristics and the results of gene detection were retrospectively analyzed.

Four cases with ABCA3 gene mutations were found; 2 patients (case 2 and case 4) had the heterozygous mutation of ABCA3 E292V. One was a 3-hour-old girl and another was a 52-day-old boy, 2 patients (case 1 and case 4) had the heterozygous mutation of ABCA3 G1221S. One was a 78-day-old boy and another was a girl, 15 years and one month old. The family history was negative for respiratory disease. Three patients (case 1, 2, 4 ) had NRDS and 2 (case 1, 2) of them were premature. One patient (case 3) had normal growth and development. She was diagnosed clinically as interstitial lung disease (ILD) after admission. The clinical outcomes of 4 cases were various. Case 1 had recurrent wheezing and inhaled corticosteroid was needed. Case 2 died because she failed to wean from mechanical ventilator. Case 3 was discharged with improvement but lost to follow-up. Case 4 grows normally.

Genetic variants within ABCA3 may be the genetic causes or background of a contributor to some unexplained refractory NRDS, and chronic lung disease developed in latter childhood. Identification of ABCA3 genetic variants in NRDS infants is important to offer genetic counseling, as well as early prognosis estimation and intervention in pediatric chronic lung disease.