Hematological phenotype analysis of fetuses and patients with hemoglobin H disease / 中华地方病学杂志

Objective:To analyze the relationship between hematological and genotype characteristics of fetuses and patients with hemoglobin (Hb) H disease and their natural disease progression.Methods:From 2010 to 2022, a total of 1 252 blood samples from fetuses and patients with Hb H disease who visited the Guangxi Zhuang Autonomous Regional Maternal and Child Health Hospital were collected (including 174 umbilical cord blood samples, 1 062 peripheral blood samples from patients over 2 years old, and 16 peripheral blood samples from patients with rare cases of genotype Hb H). Additionally, 278 peripheral blood samples were collected from patients aged 0 - 2 years old with Hb H 3.7, Hb H 4.2, Hb H CS, and Hb H WS disease for the study of trends in red blood cell development. Multiple probe hybridization and microarray comparative genomic hybridization technology combined with first-generation Sanger sequencing were used for rare mutation detection.Results:Among the 1 062 Hb H disease patients over 2 years old, 62.34% (662/1 062) had gene deletion (--/-α), of which Hb H 3.7 (-- SEA/-α 3.7) and Hb H 4.2 (-- SEA/-α 4.2) were the most common, accounting for 42.28% (449/1 062) and 19.11% (203/1 062) of the total, respectively. Among the non-deletion genotypes (--/αα T or α Tα/αα T), Hb H CS (-- SEA/α CS), Hb H WS (-- SEA/α WS) and α CSα/α CSα accounted for 16.85% (179/1 062), 16.48% (175/1 062) and 1.98% (21/1 062), respectively. The 81.12% (537/662) of patients with deletional Hb H disease showed mild to moderate anemia, with Hb H detection rates ranging from 75% to 80%. Among non-deletional Hb H disease, Hb H WS disease showed the mild (blood Hb concentration > 95 g/L in 90% of patients) phenotype while Hb H CS and Hb H QS (-- SEA/αα QS) patients had moderate to severe anemia, with Hb H detected in peripheral blood at higher levels than in other types of Hb H disease patients. Except for Hb H CS and Hb H QS, which did not show a significant increase in Hb A2 levels when complicated with β-thalassemia, Hb A2 levels were increased (> 3.5%) in all other types of Hb H disease patients. When Hb H disease was complicated with β-thalassemia, Hb H peaks were not detected in either type of Hb H disease. The results of red blood cell development trend detection showed that erythrocyte counts were elevated in patients with Hb H disease compared to their normal counterparts; whereas, blood Hb, mean erythrocyte volume (MCV) and mean erythrocyte hemoglobin content (MCH) were lower than in their normal counterparts ( P < 0.05) and decreased to the minimum at 6 months to 1 year of age. Patients with Hb H CS disease, as the most severe form of anemia, had the highest MCV values ( P < 0.001). The results of fetal cord blood with Hb H disease showed that α CSα/α CSα caused severe intrauterine anemia, followed by Hb H QS and Hb H CS. The content of Hb Bart's in umbilical cord blood was negatively correlated with the severity of anemia ( rs = - 0.58, P < 0.001). When Hb H disease was complicated with β-thalassemia, there was no significant improvement in fetal anemia, and the Hb Bart's content did not change significantly ( P > 0.05). In addition, Hb H 21.9 (-α 21.9kb/-- SEA) and Hb H 2.4 (-α 2.4/-- SEA) were common in patients with deletion rare Hb H. In patients with non-deletion rare Hb H, αα Amsterdam-A1/-- SEA and αα Hb G-Georgia/-- SEA were both first reported. Conclusions:There is heterogeneity in clinical manifestations of patients with different types of Hb H disease or same type of Hb H disease at different developmental stages. When patients with Hb H are complicated with β-thalassemia, the phenotype of patients with the deletion type is improved, while that of patients with the non-deletion type is not. Compared to normal individuals, patients with Hb H disease have lower blood Hb concentration, MCV and MCH, and more rapid physiological changes in red blood cells.

Study on blood carnitine metabolism and its influencing factors in premature infants / 国际儿科学杂志

Objective:To explore the characteristics and influencing factors of blood carnitine metabolism in premature infants.Methods:A retrospective analysis of 37 037 neonates with negative results of genetic metabolic disease screening at Guangxi Newborn Disease Screening Center from 2018 to 2021, of which 34 517 normal full-term infants were the control group and 2 520 preterm infants were the research group.According to gestational age, the preterm infants were further divided into three groups: extremely preterm group( n=232), moderately preterm group( n=324)and late preterm group( n=1 964). According to birth weight, they were divided into three groups: very low birth weight group( n=188), low birth weight group( n=1 276)and normal birth weight group( n=1 056). According to blood collection time, they were divided into three groups: 3~7 days group( n=1 990), 8~14 days group( n=342) and 15~28 days group( n=188). Tandem mass spectrometry was used to detect the levels of 31 carnitines in dried blood spots and analyze the differences in the levels of metabolic indicators in each group. Results:Carnitine levels in preterm infants are most affected by gestational age.Adjusting the physiological and pathological conditions of premature infants and other related factors, grouped by gestational age, there were differences in the levels of 31 carnitines among the groups(all P<0.05), the smaller the gestational age, the greater the difference in carnitine levels; grouped by blood collection time, there were statistically significant differences in carnitine levels between preterm infants with different blood collection age groups and full-term 3~7 days groups(all P<0.05), and showing age-related; there are differences among 31 carnitines grouped by body weight(all P<0.05), the smaller the body weight, the greater the difference in carnitine levels.Combined with the analysis of gestational age, birth weight and blood collection date, 17 indicators including C0, C2, C3, C4, C6DC, C10, C10∶1, C12, C12∶1, C14, C14∶1, C14OH, C16, C16∶1, C18, C18∶1 and C18∶1OH are important biomarkers of carnitine metabolism in premature infants. Conclusion:Carnitine in premature newborns has different metabolic differences at different gestational ages, birth weights and blood collection ages, which provides a strong basis for establishing reference standards and interpretation of preterm infants in the laboratory in this region, and provides reasonable and effective early diagnosis and treatment for clinical practice.Meanwhile, it provides an optimized program for timely detection of carnitine deficiency and carnitine supplementation to improve nutrition of premature infants.

Analysis of genetic variants in four children with congenital hyperinsulinemia / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis of four children with congenital hyperinsulinemia (CHI).@*METHODS@#The four children were subjected to high-throughput whole exome sequencing (WES). Candidate variants were validated by Sanger sequencing.@*RESULTS@#WES analysis has identified 4 variants in the ABCC8 gene and 1 variant in GLUD1, including a ABCC8 c.382G>A variant in case 1, compound heterozygous c.698T>C and c.4213G>A variants of the ABCC8 gene concomitant with a de novo 14.9 Mb microduplication of chromosome 15 in case 2, and ABCC8 c.331G>A variant in case 3, and de novo c.955T>C variant of the GLUD1 gene in case 4. Of these, c.698T>C of the ABCC8 gene and c.955T>C of the GLUD1 gene were unreported previously. Based on the American College of Medical Genetics and Genomics guidelines, the c.382G>A(p.Glu128Lys), c.698T>C(p.Met233Thr) and c.4213G>A(p.Asp1405Asn) variants of ABCC8 gene and c.955T>C(p.Tyr319His) variant of GLUD1 gene were predicted to be likely pathogenic(PM1+PM2+PP3+PP4, PM1+PM2+PM5+PP3+PP4, PM1+PM2+PP3+PP4 and PS1+PM1+PM2+PP3), and the c.331G>A (p.Gly111Arg) variant of ABCC8 gene was predicted to be uncertain significance(PM1+PM2+PP4).@*CONCLUSION@#The variants of the ABCC8 and GLUD1 genes probably underlay the pathogenesis of CHI in the four patients. Above results have facilitated clinical diagnosis and genetic counseling for the affected families.

Analysis of metabolic profile and genetic variants for newborns with primary carnitine deficiency from Guangxi / 中华医学遗传学杂志

OBJECTIVE@#To analyze the metabolic profile and genetic variants for newborns with primary carnitine deficiency (PCD) from Guangxi, China.@*METHODS@#From January 2014 to December 2019, 400 575 newborns from the jurisdiction of Guangxi Zhuang Autonomous Region Newborn Screening Center were subjected to tandem mass spectrometry (MS/MS) analysis. Newborns with positive results for PCD and their mothers were recalled for retesting. Those who were still positive were subjected to sequencing of the SLC22A5 gene.@*RESULTS@#Twenty-two newborns and 9 mothers were diagnosed with PCD, which gave a prevalence rate of 1/18 208. Sequencing of 18 newborns and 4 mothers have identified 14 types of SLC22A5 gene variants, with the common ones including c.51C>G (10/44, 22.7%), c.1195C>T (9/44, 20.5%) and c.1400C>G (7/44, 15.9%), The c.517delC(p.L173Cfs*3) and c.1031C>T(p.T344I) were unreported previously and predicted to be pathogenic (PVS1+PM2_supporting+PM3+PP4) and likely pathogenic (PM1+PM2_supporting+PM3+PP3+PP4) based on the American College of Medical Genetics and Genomics standards and guidelines.@*CONCLUSION@#c.51C>G, c.1195C>T and c.1400C>G are the most common variants underlying PCD in Guangxi.

Mutation spectrum and new mutation of phenylalanine hydroxylase gene in Guangxi region / 中华实用儿科临床杂志

Objective To investigate the characteristics of the phenylalanine hydroxylase( PAH)gene muta﹣tions in patients With phenylketonuria(PKU)in Guangxi region,in order to provide clinical data for genetic counseling and prenatal gene diagnosis. Methods Thirty－seven children diagnosed as PKU in the Maternal and Children＇s Hos﹣pital of Guangxi Zhuang Autonomous Region Were enrolled in the study betWeen January 2009 and December 2017. Ve﹣nous blood Was collected and the PAH gene sequence Was determined by Sanger sequencing after amplification With the polymerase chain reaction technique. The neW gene mutations Were defined based on the national and international literature revieW and databases. MeanWhile,100 healthy individuals Were selected as the control group for gene sequen﹣cing to confirm Whether the mutation Was a neW one. Results Thirty－seven cases of PKU Were detected for 68 muta﹣tions,With the detection rate being 91. 89%(68／74). Six mutations Were identified in exon 7,Which accounted for 31. 08% of all,exon 12(18. 92%),exon 8(10. 81%)and exon 6(10. 81%)folloWed. A total of 25 different muta﹣tions Were identified Which including 14 missense mutations(56. 00%),7 nonsense mutations(28. 00%),3 splicing junction mutations(12. 00%),and 1 deletion mutation(4. 00%). The most common mutations included c. 1223G＞A (p. R408Q),c. 728G＞A(p. R243Q)and c. 721C＞T( p. R241C),accounting for 14. 86%,13. 51%,and 10. 81%, respectively. After querying international databases,including PAH mutation database and Human Gene Mutation Data﹣base and forecasting softWare,three kinds of mutations c. 314C＞ T(p. T105I),c. 583A＞ G(p. K195E),c . 851G＞A(p. C284Y)Were verified as novel PAH gene mutations. Conclusions The mutation spectrum of the PAH gene in Guangxi has been identified. And 3 kinds of mutations have been identified. This may accumulate valuable information for gene diagnosis and prenatal diagnosis of PKU in Guangxi region.

Analysis of four carnitine-acylcarnitine translocase deficiency cases caused by homozygous mutation of SLC25A20 c.199-10T> G / 中华儿科杂志

Objective@#To investigate the clinical, biochemical and genetic features of four carnitine-acylcarnitine translocase deficiency cases.@*Methods@#Four cases diagnosed with carnitine-acylcarnitine translocase deficiency from Guangxi Maternal and Child Health Hospital were studied. DNA was extracted from dry blood filter for gene analysis. SLC25A20 gene analysis was performed in 1 case and the whole exon sequence analysis was performed in 3 cases.@*Results@#Retrospective study on unrelated carnitine-acylcarnitine translocase deficiency patients, the age of onset was 1-28 d, the age of death were 1.5-30 d, main clinical features were hypoglycemia (4 cases), arrhythmia (2 cases), sudden death (2 cases). Biochemical test showed hypoglycemia (1.2-2.0 mmol/L) , elevated creatine kinase (955-8 361 U/L) and creatine kinase isozyme(199-360 U/L), normal or decreased free carnitine level (3.70-27.07 μmol/L) , elevated long-chain acylcarnitine (palmityl carnitine 1.85-14.84 μmol/L). The gene tests showed that all 4 cases carried SLC25A20 gene c.199-10T> G homozygous mutation, inherited from their parents. By analyzing the haplotype, we found that the mutation loci of C. 199-10T> G were all in the same haplotype.@*Conclusion@#The c.199-10T> G mutation is an important molecular cause of carnitine-acylcarnitine translocase deficiency, which has relatively high frequency in Guangxi population, and is related to the founder effect.

Application of SNP-array technology in the genetic analysis of pediatric patients with growth retardation / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To explore the value of single nucleotide polymorphism array (SNP-array) for the analysis of pediatric patients with growth retardation.</p><p><b>METHODS</b>One hundred eighty one children with growth retardation were enrolled. DNA was extracted from peripheral samples from the patients, and whole genome copy number variations (CNVs) were detected using Illumina Human Cyto SNP-12. All identified CNVs were further analyzed with reference to databases including ClinGen, ClinVar, DECIPHER, OMIM and DGV as well as comprehensive review of literature from PubMed to determine their pathogenicity.</p><p><b>RESULTS</b>Forty seven patients (26%) with abnormal CNVs were detected, which included 12 known microdeletions/microduplications syndrome (26%), 10 pathogenic non-syndromic CNVs (21%), 3 numerical chromosome aberrations (6%), 3 unbalanced translocations (6%), 4 pathogenic mosaicisms (9%) and 15 cases with unknown clinical significance (32%). After excluding obvious numerical and/or structural chromosomal abnormalities, this study has detected 15 pathogenic microdeletions/microduplications sized 5 Mb or less, which may be missed by routine chromosomal karyotyping. In addition, there were 3 cases with loss of heterozygoisty (LOH) containing known or predicted imprinting genes as well as 2 cases with suspected parental consanguinity.</p><p><b>CONCLUSION</b>SNP-array technology is a powerful tool for the genetic diagnosis of children with growth disorders with advantages of high resolution and improved accuracy.</p>

Genome-wide copy number variations analysis in 64 patients with unexplained intellectual disability / 中华实用儿科临床杂志

Objective To investigate the genetic basis of patients with intellectual disability,and to assess the application of single nucleotide polymorphisms (SNP)-array in the molecular diagnosis of intellectual disability.Methods Sixty-four patients with intellectual disability who were identified in Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region from January 2013 to June of 2015 were enrolled.Genomic DNA was extracted from peripheral blood and was analyzed with Illumina Humancyto SNP-12 300K gene array chip.All identified copy number variants (CNVs) were analyzed with references from databases such as ClinVar,DECIPHER,OMIM and DGV(Database of Genomic Variants),as well as comprehensive literature review from PubMed database to determine the pathogenicity of CNVs.Results Sixteen cases of the above 64 patients were found to have CNVs with genomic alterations,including 6 cases microdeletions/microduplications associated with known syndromes,3 cases microdeletions and microduplications with clear clinical relevance (non-syndrome),1 case numerical chromosome aberration,1 case unbalanced translocation and 5 cases CNVs of unknown clinical significance.The detection rate was 25% (16/64 cases).Among these 16 abnormalities,6 cases of them could not be detected by using karyotyping analysis because their sizes were less than 5 Mb,and the smallest detected missing fragment was 0.53 Mb.Conclusion SNP-array gene chip technique with the advantages of higher efficiency,high-resolution and good accuracy,which can be applied to the genetic diagnosis of intellectual disability.

Identification of two novel mutations of MUT gene in a Chinese family affected with isolated methylmalonic acidemia / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To explore the molecular etiology for a Chinese family affected with isolated methylmalonic acidemia (MMA).</p><p><b>METHODS</b>Potential mutations of MUT, MMAA and MMAB genes in the proband were screened by PCR and Sanger sequencing. The pathogenicity of identified mutations was analyzed using Polyphen2, SIFT, HSF, DNAMAN 6.0 and Swiss-PdbViewer4.1.0 software.</p><p><b>RESULTS</b>Two novel mutations of the MUT gene, including c.581C>T (p.P194L) and c.1219A>T (p.N407Y), were discovered in the proband, which were inherited respectively from his mother and father. Bioinformatics analysis suggested that both mutations were damaging. The affected codons P194 and N407, both located in the (beta, alpha) 8 barrel domain and to which the substrate methylmalonyl-CoA is bound, are highly conserved across various species. Both mutations can disrupt the space conformation of its protein product, affecting the function of the MCM protein.</p><p><b>CONCLUSION</b>The novel mutations of MUT gene probably underlie the isolated MMA in this family.</p>

A novel compound heterozygous mutation causing 3-methylcrotonyl-CoA carboxylase deficiency / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To explore the molecular mechanism for a boy suspected with 3-methylcrotonyl-CoA carboxylase deficiency by neonatal screening.</p><p><b>METHODS</b>PCR and Sanger sequencing were used to identify potential mutations of MCCC1 and MCCC2 genes. SIFT and Polyphen-2 software was used to predict the effect of variant on the protein function and conservation of the variant across various species. Human Splicing Finder and Swiss-PdbViewer4.1.0 were applied to analyze the possible mechanism of the variant.</p><p><b>RESULTS</b>For the proband, a compound heterozygous mutation was discovered in the MCCC1 gene, namely c.539G>T (p.G180V) and c.704_711del (p.A235Vfs*4), which were inherited from his father and mother, respectively. The two mutations have disrupted the protein conformation, which in turn may impact the function of MCC protein.</p><p><b>CONCLUSION</b>The compound heterozygous mutations of the MCCC1 gene may contribute to the 3-methylcrotonyl-CoA carboxylase deficiency manifested by the patient.</p>

Analysis of mass spectrometric detection in 21 neonatal with neonatal intrahepatic cholestasis disease / 实用医学杂志

Objective To analyze blood Met、 Phe 、Tyr、 Arg、 Cit、 Orn、 Ser、 Thr、 C0、 C2、 C3、 C14、C14 ∶ 1 , C16 , C16 ∶ 1 , C18 , C18 ∶ 1 and urine 4-OH-PHPLA , 4-OH-PHPPA level of NICCD patient and discuss the application value of diagnosis NICCD. Methods From May 2011 to May 2015, 21 NICCD patient were diagnose in Guangxi Newborn Screening Center. Meanwhile, 100 normal children were selected as the control group. Blood Met, Phe, Tyr and other factors and urine 4-OH-PHPLA, 4-OH-PHPPA level were analyzed by SPSS. Results In the experimental group, blood Met, Phe, Tyr and many other indexes and urine 4-OH-PHPLA, 4-OH-PHPPA level were higher and blood Orn/Cit were lower than the control group(P 0.05). Conclusion NICCD patient has abnormal biochemical index. Blood test by TMS and urine test by GC-MS are very important in NICCD diagnosis.

ASS1 gene mutation in a neonate with citrullinemia type I / 中华儿科杂志

<p><b>OBJECTIVE</b>To identify the genetic mutation in ASS1 gene in a Chinese family with citrullinemia typeI, which may provide a basis for the diagnosis and genetic counseling.</p><p><b>METHOD</b>Genomic DNA was isolated from peripheral blood samples of the family members. Mutation analysis of ASS1 gene was carried out by PCR and Sanger sequencing. Biostructural analysis of the mutated ASS1 was completed by Phyre server.</p><p><b>RESULT</b>Double heterozygous mutations in the proband were identified: c.951delT (F317LfsX375) and c.1087C>T (R363W), which were confirmed in the proband's father and mother, respectively. It was found that the c.951delT mutation might change the formation of a dimer or a tetramer and the function of ASS1 protein.</p><p><b>CONCLUSION</b>Double heterozygous mutations for c.951delT and c.1087C>T have been found in a proband with citrullinemia typeI. The c.951delT is a novel mutation in citrullinemia typeI, which may change the configuration of ASS1 protein and result in ASS1 dysfunction.</p>

Gene array analysis in 56 cases of children with growth retardation / 临床儿科杂志

Objective To investigate the genetic basis of the children with growth retardation. Methods From January to October 2013, the 56 patients with growth retardation were enrolled in this study. Genomic DNA was extracted from peripheral blood and was analyzed with gene array chips. Results Abnormalities were found in 12 patients (6 cases of sex chromosome abnormalities and 6 cases of autosomal aberration) and the detection rate was 21.4%. Four patients had the copy-number variations of smaller than 2.5Mb in size which could not be found by karyotyping analysis. Conclusions SNP-array gene chip could be used in the genetic diagnosis of growth retardation.