Screening and gene mutations analysis for neonates with methylmalonic aciduria / 中华围产医学杂志

Objective To investigate the characteristics of neonatal methylmalonic aciduria (MMA)regarding clinical manifestations,laboratory findings,gene mutations,treatments and prognosis.Methods Acylcamitine levels in blood samples of 207 308 neonates born from January 2016 to December 2017 in Xuzhou were detected by liquid chromatography tandem mass spectrometry and the abnormal results were further confirmed by detecting organic acids in urine samples with gas chromatography-mass spectrometry and gene sequencing analysis.Patients with isolated MMA were treated with dietary control and levocarnitine,while those complicated by homocysteinemia were treated with vitamin B12,levocarnitine,glycine betaine and calcium folinate.Clinical manifestations,laboratory findings,imaging features,genotypes,treatments and prognosis of patients with MMA were retrospectively analyzed.Paired sample t-test was applied for statistical analysis.Results MMA was eventually diagnosed in 12 patients,among which three were isolated MMA and nine were complicated by homocysteinemia.The three isolated MMA cases failed to response to vitamin B12 treatment without any symptoms on diagnosis.However,vitamin B12 was effective for the other nine patients,among which four had no clinical symptoms on diagnosis and five had manifestations such as slow response,recurrent vomiting,poor feeding,dyspnea,anemia and jaundice.Abnormal results of cranial MRI included bilateral basal ganglia damage,enlarged extracranial space,ventriculomegaly and changes in white matter.All patients underwent genetic analysis and three were found with MUT gene mutations and nine with MMACHC gene mutations.MUT gene mutations were classified into five types,including c.I106G＞A,c.1880A＞G,c.441T＞A,c.581C＞T and c.1741C＞T.Eight types of MMACHC gene mutations were identified,including c.609G＞A,c.658_660delAAG,c.482G＞A,c.1A＞G,c.567dupT,c.80A＞G,c.276+1G＞A and c.228_23 l delTGAC.Two mutations,c.276+lG＞A and c.228 23 ldelTGAC,were novel mutations.The most common mutation in MMACHC gene was c.609G＞A,followed by c.658_660delAAG and c.482G＞A.One of the isolated MMA patients died after refusing treatments and the other two showed significant decrease in serum propionylcarnitine,propionylcarnitine to acetylcarnitine ratio,serum homocysteine and methylmalonic acid and methylcitric acid in urine after treatment.Moreover,of the two patients who were alive at follow-up,one experienced normal growth and development and the other suffered from growth retardation.The ratio of propionylcamitine to acetylcarnitine and the levels of serum propionylcarnitine,serum homocysteine and methylmalonic acid and methylcitric acid in urine were significantly decreased in the nine patients with MMA complicated by homocystinuria after one month of treatment [0.88±0.35 vs 0.13±0.05,(7.12±1.90) μ mol/L vs (3.18±1.08) μ mol/L,(136.48±38.14) μ mol/L vs (34.41±17.33) μmol/L,103.51±69.62vs 5.35±2.15 and 7.95±6.88 vs 1.02±0.48,t=-6.166,-6.687,-12.941,-4.208 and-3.015,respectively,all P＜0.05].Two deaths,three asymptomatic and four psychomotor retardation patients were reported during follow-up.Conclusions Newborn screening with liquid chromatography tandem mass spectrometry is important for early diagnosis of MMA.MMACHC gene defects are the main causes of MMA in Xuzhou area and the predominant one is c.609G＞A mutation.Prognosis of MMA might be related to disease type,age of onset and patient's reactivity to vitamin B12.

Screening and SLC22A5 gene mutations of the patients with primary carnitine deficiency / 中华实用儿科临床杂志

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.

Analysis of neonatal hyperphenylalaninemia screening and therapeutic effect in Xuzhou from 2003 to 2015 / 中华围产医学杂志

Objective To investigate the prevalence,clinical classification,treatment and prognosis of neonatal hyperphenylalaninemia(HPA) in Xuzhou area,China.Methods Infants born between July 1,2003 and July 1,2015 in Xuzhou area were investigated.Heel blood samples of neonates were collected at 72 hours after birth,and the concentration of blood phenylalanine(Phe) was determined by fluorescent quantitative method in Xuzhou Maternity and Child Health Care Station Neonatal Disease Screening Center.Differential diagnosis was performed in all 265 cases diagnosed as HPA by urinary pterin analysis and dihydropteridine reductase activity determination.The blood Phe concentration and mental development were followed up regularly in infants with HPA.Mutations of phenylalanine hydroxylase (PAH) gene were analyzed by gene sequencing.The relationship between blood Phe concentration and mental development was analyzed by Bivariate correlation analysis.Results (1) The prevalence of HPA in neonates in Xuzhou was 1/4 635.Among the 265 confirmed HPA cases,260 cases(98.11％) had PAH deficiency,including 90(33.96％) classical phenylketonuria(PKU),84(31.70％) mild PKU and 86(32.45％) mild HPA.The other five patients(1.89％) diagnosed with tetrahydrobiopterin (BH4) deficiency all had 6-pyruvoyl tetrahydropteim synthase(PTPS) deficiency.(2) Among the 265 HPA cases,26 cases refused any treatment,including five cases of PTPS deficiency and 21 cases of PKU.Of the five patients with PTPS deficiency,two died and the other three had normal mental and physical development.Twenty-one PKU patients who refused treatment had mental retardation of various degrees.Among 153 PKU patients who received medical treatment,three died and 12 were lost to follow-up.(3) For 138 PKU patients who received dietary treatment and follow-up,the ages at the last visit were two months to 12 years,116 of them had normal mental development,the remaining 22 patients had mental retardation,and a negative correlation was observed between mental development and the average Phe concentration.(4) Thirty-five patients with PAH deficiency underwent gene sequencing,and 22 kinds of mutations of PAH gene were detected.Conclusions The prevalence of HPA in Xuzhou area is higher than the average national level.With early diagnosis and standard treatment,most of PKU neonates can have normal mental development.Phe level control is an important factor for mental development.

Analysis of screening and therapeutic effect of congenital hypothyroidism / 临床儿科杂志

Objective To explore neonatal screening and therapeutic effects of congenital hypothyroidism (CH) in Xuzhou. Methods Data of neonatal heel blood thyroid stimulating hormone (TSH) tested with time-resolved lfuoroimmunoassay from July 2003 to July 2015 were retrospectively analyzed; The cases with positive screening tests were called back for further examination of the serum thyroid function (TSH,FT 3,FT 4 ) by chemiluminescence immunoassay method. The CH patients were given levothyroxine replacement. A total of 686 patients with CH treated routinely for 1 years later (CH group) and 650 matched healthy children (control group) were included in the study. The physical development was monitored regularly. The neurodevelopment was tested at 1 and 3 years old. Results In Xuzhou 1228289 neonates were screened during 12 years,of them 950 cases were diagnosed with CH and the incidence was 1/1293 . Among 635 CH patients who received treatment and follow-up regularly for 2 years,?488 cases ( 76 . 85%) were evaluated to have permanent hypothyroidism and 147 cases ( 23 . 15%) have transient hypothyroidism. There were no signiifcant differences in developmental quotient between the CH group and the control group at 1 and 3 years old (P?>?0 . 05 ). Conclusions Neonatal disease screening is an effective measure for early diagnosis of CH; the physical and mental development are normal in CH patients after early replacement therapy.