Prenatal diagnosis of X-linked adrenoleukodystrophy in 20 pedigrees / 中华围产医学杂志

ABSTRACT

Objective:To summarize the characteristics of genetic variation and prenatal diagnosis in pedigrees with X-linked adrenoleukodystrophy (X-ALD) and elucidate the value of prenatal diagnosis in preventing the birth of children with X-ALD.Methods:Twenty pedigrees, clinically diagnosed with X-ALD in Peking University First Hospital from November 2012 and March 2019, were included in this retrospective study. Genomic DNA was extracted from peripheral blood and amniotic fluid or chorionic villi samples of probands and their families for detecting variants in ATP-binding cassette subfamily D member 1 ( ABCD1) gene using polymerase chain reaction (PCR)-Sanger sequencing. Linkage analysis was also performed on five microsatellite markers near ABCD1 gene to exclude maternal contamination. Characteristics of ABCD1 gene variants and prenatal diagnosis of X-ALD pedigrees were summarized by descriptive statistics. Results:Twenty ABCD1 gene variants were identified in the 20 pedigrees. The variants in three probands that were not detected by next-generation sequencing were identified by PCR-Sanger sequencing. Among the mothers of the 20 probands, 17 carried ABCD1 variants and three did not. We performed 24 prenatal diagnoses on 20 pregnancies (24 fetuses) and identified eight fetuses with variants who were finally terminated. The 16 cases without variants were born alive. The validation results obtained after termination or delivery were consistent with those performed prenatally. Conclusions:No hotspot variants in ABCD1 gene are detected in these X-ALD patients and most variants are maternally inherited. PCR-Sanger sequencing is an effective method for detecting ABCD1 variants. Prenatal diagnosis for mothers who had a body with X-ALD could prevent another one from birth.