Molybdenum cofactor deficiency caused by MOCS1 gene mutation: a case report
WU Lian-Hong, JIANG Yan, HU Yue
Department of Neurology, Children's Hospital of Chongqing Medical University/National Clinical Research Center for Child Health and Disorders/Ministry of Education Key Laboratory of Child Development and Disorders/Chongqing Key Laboratory of Pediatrics, Chongqing 400014, China
患儿男，1月龄时因左手抖动1周就诊。血尿酸降低，头颅MRI示脑软化、萎缩、囊变，婴儿期出现小头畸形、特殊面容（长脸、长额头、前额隆起、长人中、低鼻梁、颜面部浮肿、厚下嘴唇）、下肢肌张力增高及严重全面发育迟缓。患儿行全外显子组测序示MOCS1基因存在c.217C > T （p.R73W）纯合变异，来源于父母，该变异判定为“可能致病的”。根据患儿临床表现及基因检查明确诊断为钼辅酶缺乏症A型，该病为国内首次报道。
Abstract：A boy attended the hospital at the age of 1 month due to left hand tremor for 1 week. A blood test showed a reduction in serum uric acid and a cranial MRI showed encephalomalacia, atrophy, and cystic changes. The boy had microcephalus, unusual facial features (long face, long forehead, protruded forehead, long philtrum, low nasal bridge, facial swelling, and thick lower lip), hypertonia of lower extremities, and severe global developmental delay. Whole-exome sequencing performed for the boy detected a homozygous mutation, c.217C > T(p.R73W), in the MOCS1 gene, which came from his parents and was determined as "possibly pathogenic". The boy was diagnosed with molybdenum cofactor deficiency type A based on clinical manifestations and gene test results. This disease is reported for the first time in China.
Alonzo Martínez MC, Cazorla E, Cánovas E, et al. Molybdenum cofactor deficiency:mega cisterna magna in two consecutive pregnancies and review of the literature[J]. Appl Clin Genet, 2020, 13:49-55.
[2]
Hitzert MM, Bos AF, Bergman KA, et al. Favorable outcome in a newborn with molybdenum cofactor type A deficiency treated with cPMP[J]. Pediatrics, 2012, 130(4):e1005-e1010.
[3]
Schwahn BC, Van Spronsen FJ, Belaidi AA, et al. Efficacy and safety of cyclic pyranopterin monophosphate substitution in severe molybdenum cofactor deficiency type A:a prospective cohort study[J]. Lancet, 2015, 386(10007):1955-1963.
[4]
Reiss J, Hahnewald R. Molybdenum cofactor deficiency:mutations in GPHN, MOCS1, and MOCS2[J]. Hum Mutat, 2011, 32(1):10-18.
[5]
Reiss J, Christensen E, Kurlemann G, et al. Genomic structure and mutational spectrum of the bicistronic MOCS1 gene defective in molybdenum cofactor deficiency type A[J]. Hum Genet, 1998, 103(6):639-644.
[6]
Nagappa M, Bindu PS, Taly AB, et al. Child neurology:molybdenum cofactor deficiency[J]. Neurology, 2015, 85(23):e175-e178.
[7]
Scelsa B, Gasperini S, Righini A, et al. Mild phenotype in molybdenum cofactor deficiency:a new patient and review of the literature[J]. Mol Genet Genomic Med, 2019, 7(6):e657.
[8]
Sass JO, Gunduz A, Araujo Rodrigues Funayama C, et al. Functional deficiencies of sulfite oxidase:differential diagnoses in neonates presenting with intractable seizures and cystic encephalomalacia[J]. Brain Dev, 2010, 32(7):544-549.
[9]
Zaki MS, Selim L, El-Bassyouni HT, et al. Molybdenum cofactor and isolated sulphite oxidase deficiencies:clinical and molecular spectrum among Egyptian patients[J]. Eur J Paediatr Neurol, 2016, 20(5):714-722.
[10]
BridgeBio Pharma, Inc.. Nulibry:treatment for molybdenum cofactor seficiency (MoCD) type A[EB/OL]. (2019-12-03)[2021-02-24]. https://www.drugs.com/nda/bbp_870_191203.html.
