Azienda Sanitaria Provinciale di Messina - Neonatal Intensive Care Unit, Barone Romeo Hospital, Patti, ME, Italy.
Ital J Pediatr. 2022 Sep 5;48(1):164. doi: 10.1186/s13052-022-01356-w.
Multiple acyl-CoA dehydrogenase deficiency (MADD) or glutaric aciduria type II is an extremely rare autosomal recessive inborn error of fatty acid beta oxidation and branched-chain amino acids, secondary to mutations in the genes encoding the electron transfer flavoproteins A and B (ETFs; ETFA or ETFB) or ETF dehydrogenase (ETFDH). The clinical manifestation of MADD are heterogeneous, from severe neonatal forms to mild late-onset forms.
We report the case of a preterm newborn who died a few days after birth for a severe picture of untreatable metabolic acidosis. The diagnosis of neonatal onset MADD was suggested on the basis of clinical features displaying congenital abnormalities and confirmed by the results of expanded newborn screening, which arrived the day the newborn died. Molecular genetic test revealed a homozygous indel variant c.606 + 1 _606 + 2insT in the ETFDH gene, localized in a canonical splite site. This variant, segregated from the two heterozygous parents, is not present in the general population frequency database and has never been reported in the literature.
Recently introduced Expanded Newborn Screening is very important for a timely diagnosis of Inherited Metabolic Disorders like MADD. In some cases which are the most severe, diagnosis may arrive after symptoms are already present or may be the neonate already died. This stress the importance of collecting all possible samples to give parents a proper diagnosis and a genetic counselling for future pregnacies.
多种酰基辅酶 A 脱氢酶缺乏症(MADD)或戊二酸血症 II 型是一种极其罕见的常染色体隐性遗传性脂肪酸 β 氧化和支链氨基酸代谢障碍,继发于编码电子转移黄素蛋白 A 和 B(ETFA 或 ETFB)或 ETF 脱氢酶(ETFDH)的基因突变。MADD 的临床表现呈异质性,从严重的新生儿型到轻度晚发型。
我们报告了一例早产儿的病例,该患儿在出生后几天因无法治疗的代谢性酸中毒而死亡,呈现出严重的症状。根据新生儿期发病的临床表现伴有先天性异常,且新生儿扩大筛查结果证实了这一诊断,而这些结果是在患儿死亡当天得出的。分子遗传学检测显示 ETFDH 基因 c.606 + 1 _606 + 2insT 杂合缺失变异,位于经典剪接位点。该变异在两个杂合子父母中均存在,在一般人群频率数据库中不存在,也从未在文献中报道过。
最近引入的新生儿扩大筛查对于及时诊断 MADD 等遗传性代谢疾病非常重要。在某些情况下,即使在症状已经出现后,也可能无法及时诊断,或者新生儿已经死亡。这强调了收集所有可能样本的重要性,以便为父母提供正确的诊断和未来妊娠的遗传咨询。