ABSTRACT
Objective@#To study the prevalence, clinical and genetic characteristics of primary carnitine deficiency (PCD).@*Methods@#From January 2013 to December 2017, 720 667 newborns and their mothers were tested for PCD by tandem mass spectrometry. Potential mutations of carnitine transporter gene SLC22A5 among suspected PCD patients were analyzed. Dietary guidance and L-carnitine supplementation were provided to the parents. Growth and intelligence development were surveyed during follow-up.@*Results@#In total 21 neonates and 6 mothers were diagnosed with PCD, which yielded an incidence of 1 in 34 317. Eighteen SLC22A5 mutations were detected, which included 4 novel mutations, namely c. 1484T>C, c. 394-1G>T, c. 431T>C and c. 265-266insGGCTCGCCACC. Eighteen patients were found to carry compound heterozygous mutations and 3 have carried homozygous SLC22A5 mutations. Three mothers carried compound heterozygous mutations and 2 carried homozygous mutations. Common mutations included c. 1400C>G (42.3%), c. 760C>T (11.5%) and c. 51C>G (7.7%). During the 8 ~ 42 month follow-up, neonates with PCD showed no clinical symptoms but normal growth. Blood level of free carnitine was raised in all mothers after the treatment.@*Conclusion@#The incidence of neonatal PCD in Henan is 1 in 34 317, with the most common mutation being c. 1400C>G. Above finding has enriched the spectrum of SLC22A5 gene mutations.
ABSTRACT
Objective To investigate the clinical features and SLC22A5 gene mutation types in patients with primary carnitine deficiency(PCD).Methods The free carnitine(CO) and acylcarnitine levels in the blood of 210 908 neonates from newborn screening program and 576 children with suspected clinical inherited metabolic diseases were measured by using liquid chromatography tandem mass spectrometry method during September 2015 to December 2017,after that the SLC22A5 gene mutations were analyzed in the children with low CO level and the diagnosis was made.The clinical characteristics,laboratory findings,genotypes,treatment and prognosis were retrospectively analyzed in patients.Paired sample t test was used to compare the biochemical indexes of patients before and after the treatments.Results Ten children were diagnosed with PCD(9 cases from newborn screening program,1 case from clinical patients),and 7 children were diagnosed with maternal carnitine deficiency.After treatment with oral Levocarnitine,the free carnitine and acylcarnitine of the patients returned to the normal levels.The clinical symptoms disappeared in 1 patient out of clinical patients,and the other 16 patients from newborn screening program were asymptomatic and showed normal growth and development.Seventeen patients got genetic analysis,and 10 types of mutations were found,including c.1400C ＞ G,c.1462C ＞ T,c.797C ＞ T,c.95A ＞ G,c.92C ＞ T,c.1093A ＞ C,c.761G ＞ A,c.865C ＞ T,c.428C ＞ T,c.1195C ＞ T,among which two of them (c.1093A ＞ C and c.92C ＞ T) were novel mutations.The most common mutation of SLC22A5 gene was c.1400C ＞ G.Conclusions Liquid chromatography tandem mass spectrometry technology is sufficient to screen newborns and maternal carnitine deficiency,and the c.1400C ＞ G mutation is found at the highest frequency in Xuzhou area.If patients receive early treatment,they may have a good prognosis.
ABSTRACT
Objective To explore the clinical feature and gene types in patients with primary carnitine deficiency. MethodsClinical data of 6 patients with primary carnitine deficiency and 2 patients with maternal carnitine deficiency found in the screening by tandem mass spectrometry technology during December 2013 to December 2016 were retrospectively analyzed. Results The free carnitine levels of 8 patients in initial and recall screening were 5.85±1.65 μmol/L and 5.22±1.02 μmol/L. Two pathogenic alleles were detected in each patient with primary carnitine deficiency by genetic and metabolic disease panel based on Ion Torrent semiconductor sequencing. After treatment with oral L-carnitine, the free carnitine levels of 6 patients with primary carnitine deficiency were 20.24±3.88 μmol/L. The carnitine levels returned to normal after mixed feeding for one week in 2 patients with maternal carnitine deficiency, and no genetic diagnosis was carried out. Conclusion Primary carnitine deficiency can be effectively detected using tandem mass spectrometry technology and next generation sequencing panel and the prognosis is good with early standard treatment.