Screening strategy and genetic mutation analysis of citrin deficiency among newborns in Xuzhou / 中国新生儿科杂志

Objective:To study the incidence, clinical features and genetic mutation profiles of neonatal intrahepatic cholestasis caused by citrin deficiency (NICCD) using screening strategy.Methods:From September 2015 to September 2020, neonates in Xuzhou area were prospectively screened for genetic metabolic diseases using tandem mass spectrometry. Suspected infants were further confirmed using urinary organic acid test and SLC25A13 gene mutation analysis. The clinical manifestations, biochemical and gene mutation results, treatment and prognosis of the confirmed cases were analyzed.Results:A total of 468,494 live-birth newborns were screened with 112 cases suspected and 95 cases received urinary organic acid test and SLC25A13 gene mutation analysis. 13 cases of NICCD were diagnosed with a prevalence of 1/36,038. Most confirmed cases presented with delayed disappearance of neonatal jaundice, feeding difficulties and poor weight gain. Biochemical changes included increased bile acid, abnormal liver enzymes, increased alpha-fetoprotein, hypoglycemia, decreased hemoglobin, abnormal coagulation function and increased blood ammonia. Tandem mass spectrometry showed increased citrulline, methionine, arginine, tyrosine and phenylalanine, and in some cases with slightly increased acylcarnitine. Urine organic acid analysis mainly showed increased 4-hydroxyphenyllactic acid and 4-hydroxyphenylpyruvate. All confirmed cases received genetic mutation tests and a total of 13 mutation loci were detected, including c.852_855delTATG, c.511dupG, c.1638_1660dup, IVS16ins3kb, c.1078C>T, c. 615+5G>A, c.742G>A, c.44G>A, c.1311+1G>A, c.1399C>T, c.889G>T, c.1177+1G>A, c.1841+3_1841+4del, among which, c.852_855delTATG was the most common one. A total of 5 novel mutation loci were discovered in this study with c.1841+3_1841+4del, c.511dupG and c.889G>T predicted as pathogenic variants. Special formula of lactose-free and fortified medium-chain triglyceride (MCT) were used in confirmed cases and most of the symptoms were relieved within 1 year and abnormal indicators significantly improved.Conclusions:The prevalence of NICCD in Xuzhou was 1/36,038. c.852_855delTATG mutation is the most frequent one. Five novel mutation loci are discovered, expanding the SLC25A13 gene mutation spectrum. Most infants with NICCD have a good prognosis, requiring early diagnosis, treatment and life-long follow-up.

Clinical characteristics and genetic analysis of isobutyryl CoA dehydrogenase deficiency in Xuzhou:population screening results / 中国新生儿科杂志

Objective:To study the clinical features and genetic characteristics of isobutyryl-CoA dehydrogenase deficiency (IBDD) of neonates in Xuzhou area.Methods:From October 2016 to October 2021, neonates diagnosed with IBDD using tandem mass spectrometry in Xuzhou area were retrospectively studied. Their clinical phenotypes and genotypes, clinical diagnosis, treatment and follow-up were analyzed.Results:A total of 510 057 neonates were screened and 10 cases of IBDD were diagnosed. The 10 IBDD cases showed increased butyryl carnitine (C4), C4/C2 and C4/C3 during screening and follow-up tests. One case had transient elevated transaminase and one case showed delayed language development. The other 8 cases were otherwise normal. A total of 16 mutation loci of acyl-CoA dehydrogenase 8 (ACAD8) gene were found, including 10 unreported loci: c.567+8C>T, c.213G>T, c.553C>T, c.1190T>C, c.1060G>A, c.494G>A, c.771C>A, c.962A>T, c.715A>G and c.731G>A. Genetic mutations were found in Exon 3, Exon 4, Exon 5, Intron 5, Exon 7, Exon 9 and Exon 10. The hot spots of mutations were c.1176G>T, c. 286G>A and c.1000C>T.Conclusions:IBDD is a rare disease without specific clinical manifestations. Neonatal metabolic disease screening combined with urinary organic acid tests and genetic sequencing can be used for early detection and diagnosis of IBDD. No serious adverse outcome is found in IBDD patients during short-term follow-up, however, long-term follow-up is recommended.

Quality monitoring and evaluation of neonatal diseasescreening in Zhejiang Province / 预防医学

Abstract@#Neonatal disease screening is a major tool for prevention of birth defects, and monitoring and evaluation of neonatal disease screening facilitates the improvements in screening quality and efficiency. A strict quality control of screening, diagnosis, treatment and follow-up of neonatal diseases is performed in Zhejiang Provincial Center for Quality Control of Neonatal Disease Screening. In this study, the data pertaining to screening of neonatal inherited metabolic diseases, hearing loss and congenital heart diseases were collected in Zhejiang Province from 2018 to 2020, and the screening rate, recall rate of suspected screening-positive neonates, and detection rate of diseases were calculated to assess the quality of neonatal disease screening. The screening rate and recall rate of neonatal inherited metabolic diseases, hearing loss and congenital heart diseases were high in Zhejiang Province, and the detection of screened diseases was stable, indicating a high overall quality of neonatal disease screening. Increasing the impact of neonatal disease screening and consolidating the screening achievements should be given a high priority during the future quality control of neonatal disease screening in Zhejiang Province.

Screening results of neonatal diseases and exploration of management mode in Yichang in 2017-2019 / 公共卫生与预防医学

Objective To retrospectively analyze the results of neonatal diseases screening in Yichang from 2017 to 2019, understand the incidence and recall of the diseases, and explore the management mode of neonatal disease screening suitable for this region. Methods The subjects were newborns who were delivered in Yichang midwifery institutions from 2017 to 2019 and were screened for neonatal diseases. Heel blood of the newborns was collected for the screening of neonatal diseases, including congenital hypothyroidism (CH), phenylketonuria (PKU), G6PD deficiency, congenital adrenal hyperplasia (CAH) and thalassemia. Those newborns with positive initial screening were recalled for reexamination and confirmation. The recall rates of different diseases were compared by Chi-square test. Results There were 85 891 live births in Yichang area from 2017 to 2019, and 84 063 cases were screened for neonatal diseases, with a screening rate of 97.87%. A total of 6 043 cases were positive in the initial screening, of which 5,047 cases were recalled, with a recall rate of 83.52%. The recall rates of the traditional two diseases (CH and PKU) and the new three diseases (CAH, G6PD deficiency and thalassemia) were significantly different ( χ2= 197.93, P＜0.01). A total of 501 cases were diagnosed. The incidence rate of CH was 1/1,911, the incidence rate of PKU was 1/12 009, the incidence rate of CAH was 1/28 021, the incidence rate of G6PD deficiency was 1/1 121, and the incidence rate of thalassemia was 1/226. Conclusions The neonatal disease screening rate increased year by year in Yichang, but the recall rate of suspicious positive initial screenings decreased. It is necessary to explore a more suitable management mode for the five neonatal disease screenings in this region, improve the recall rate of children with positive screening, reduce the incidence of disabled children, and improve the quality of the birth population.

Application of tandem mass spectrometry in newborn genetic metabolic disease screening / 中华检验医学杂志

Inherited metabolic disorders, also known as congenital metabolic diseases, refer to a group of diseases that cause a series of clinical symptoms due to gene mutations, such as enzyme deficiency, dysfunction of cell membrane or receptor deficiency, resulting in biochemical metabolic disorders, accumulation of intermediate or bypass metabolites, or lack of final metabolites. Inherited metabolic disordersoften occur in childhood, progressively aggravating, irreversible nervous system damage, and even death. Tandem mass spectrometry (MS/MS) has been widely used in newborn screening abroad and in China. This technology not only expands the screening spectrum of newborn screening, but also improves the screening efficiency, specificity and sensitivity, which opens up a new field for disease screening. With deepening the understanding of the mechanism of inherited metabolic disorders and mass spectrometry technology, its clinical application becomes more significant in diseases screening and diagnosing.