Jwa Hye Jeong, Lee Keon Su, Kim Gu Hwan, Yoo Han Wook, Lim Han Hyuk
Department of Pediatrics, Chungnam National University School of Medicine, Daejeon, Korea.
Medical Genetics Clinic and Laboratory, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, Seoul, Korea.
Korean J Pediatr. 2014 Sep;57(9):416-9. doi: 10.3345/kjp.2014.57.9.416. Epub 2014 Sep 30.
X-linked adrenoleukodystrophy (X-ALD) is a rare peroxisomal disorder, that is rapidly progressive, neurodegenerative, and recessive, and characteristically primary affects the central nervous system white matter and the adrenal cortex. X-ALD is diagnosed basaed on clinical, radiological, and serological parameters, including elevated plasma levels of very long chain fatty acids (VLCFA), such as C24:0 and C26:0, and high C24:0/C22:0 and C26:0/C22:0 ratios. These tests are complemented with genetic analyses. A 7.5-year-old boy was admitted to Department of Pediatrics, Chungnam National University Hospital with progressive weakness of the bilateral lower extremities. Brain magnetic resonance imaging confirmed clinically suspected ALD. A low dose adrenocorticotropic hormone stimulation test revealed parital adrenal insufficiency. His fasting plasma levels of VLCFA showed that his C24:0/C22:0 and C26:0/C22:0 ratios were significantly elevated to 1.609 (normal, 0-1.390) and 0.075 (normal, 0-0.023), respectively. Genomic DNA was extracted from peripheral whole blood samples collected from the patient and his family. All exons of ABCD1 gene were amplified by polymerase chain reaction (PCR) using specific primers. Amplified PCR products were sequenced using the same primer pairs according to the manufacturer's instructions. We identified a missense mutation (p.Arg163Leu) in the ABCD1 gene of the proband caused by the nucleotide change 488G>T in exon 1. His asymptomatic mother carried the same mutation. We have reported an unpublished mutation in the ABCD1 gene in a patient with X-ALD, who showed increased ratio of C24:0/C22:0 and C26:0/C22:0, despite a normal VLCFA concentrations.
X连锁肾上腺脑白质营养不良(X-ALD)是一种罕见的过氧化物酶体疾病,呈快速进展性、神经退行性且为隐性遗传,其特征是主要影响中枢神经系统白质和肾上腺皮质。X-ALD根据临床、影像学和血清学参数进行诊断,包括血浆中极长链脂肪酸(VLCFA)水平升高,如C24:0和C26:0,以及高C24:0/C22:0和C26:0/C22:0比值。这些检测辅以基因分析。一名7.5岁男孩因双下肢进行性无力入住忠南国立大学医院儿科。脑部磁共振成像证实了临床怀疑的ALD。低剂量促肾上腺皮质激素刺激试验显示部分肾上腺功能不全。他空腹血浆VLCFA水平显示其C24:0/C22:0和C26:0/C22:0比值分别显著升高至1.609(正常范围0 - 1.390)和0.075(正常范围0 - 0.023)。从患者及其家人采集的外周全血样本中提取基因组DNA。使用特异性引物通过聚合酶链反应(PCR)扩增ABCD1基因的所有外显子。根据制造商说明,使用相同引物对扩增的PCR产物进行测序。我们在先证者的ABCD1基因中鉴定出一个错义突变(p.Arg163Leu),由外显子1中的核苷酸变化488G>T引起。他无症状的母亲携带相同突变。我们报告了一名X-ALD患者中ABCD1基因的一个未发表突变,该患者尽管VLCFA浓度正常,但C24:0/C22:0和C26:0/C22:0比值升高。