Objective This study aimed to comprehensively analyze and compare the clinicopathological features and prognosis of Chinese patients with human epidermal growth factor receptor 2(HER2)-low early breast cancer(BC)and HER2-IHC0 BC. Methods Patients diagnosed with HER2-negative BC(N=999)at our institution between January 2011 and December 2015 formed our study population.Clinicopathological characteristics,association between estrogen receptor(ER)expression and HER2-low,and evolution of HER2 immunohistochemical(IHC)score were assessed.Kaplan-Meier method and log-rank test were used to compare the long-term survival outcomes(5-year follow-up)between the HER2-IHC0 and HER2-low groups. Results HER2-low BC group tended to demonstrate high expression of ER and more progesterone receptor(PgR)positivity than HER2-IHC0 BC group(P<0.001).The rate of HER2-low status increased with increasing ER expression levels(Mantel-Haenszel χ2 test,P<0.001,Pearson's R=0.159,P<0.001).Survival analysis revealed a significantly longer overall survival(OS)in HER2-low BC group than in HER2-IHC0 group(P=0.007)in the whole cohort and the hormone receptor(HR)-negative group.There were no significant differences between the two groups in terms of disease-free survival(DFS).The discordance rate of HER2 IHC scores between primary and metastatic sites was 36.84%. Conclusion HER2-low BC may not be regarded as a unique BC group in this population-based study due to similar clinicopathological features and prognostic roles.

Objective To investigate the disease spectrum and pathogenic genes of inherited metabolic disorder(IMD)among neonates in Gansu Province of China.Methods A retrospective analysis was conducted on the tandem mass spectrometry data of 286 682 neonates who received IMD screening in Gansu Provincial Maternal and Child Health Hospital from January 2018 to December 2021.A genetic analysis was conducted on the neonates with positive results in tandem mass spectrometry during primary screening and reexamination.Results A total of 23 types of IMD caused by 28 pathogenic genes were found in the 286 682 neonates,and the overall prevalence rate of IMD was 0.63‰(1/1 593),among which phenylketonuria showed the highest prevalence rate of 0.32‰(1/3 083),followed by methylmalonic acidemia(0.11‰,1/8 959)and tetrahydrobiopterin deficiency(0.06‰,1/15 927).In this study,166 variants were identified in the 28 pathogenic genes,with 13 novel variants found in 9 genes.According to American College of Medical Genetics and Genomics guidelines,5 novel variants were classified as pathogenic variants,7 were classified as likely pathogenic variants,and 1 was classified as the variant of uncertain significance.Conclusions This study enriches the database of pathogenic gene variants for IMD and provides basic data for establishing an accurate screening and diagnosis system for IMD in this region.

Objective:To explore the genetic basis of eighteen patients with tetrahydrobiopterin deficiency (BH4D) from Gansu Province.Methods:Eighteen patients diagnosed with BH4D at Gansu Provincial Maternal and Child Health Care Hospital from January 2018 to December 2021 were selected as the study subjects. Whole exome sequencing was carried out, and candidate variants were verified by Sanger sequencing.Results:All of the thirty-six alleles of the eighteen patients were successfully determined by molecular genetic testing. Sixteen patients were found to harbor variants of the PTS gene, and two had harbored variants of the QDPR gene. Ten variants were detected in the PTS gene, with the most common ones being c. 259C>T (34.38%) and c. 286G>A (15.63%). Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the c. 259C>T was classified as a pathogenic variant, whilst the c. 286G>A, c. 166G>A, c. 200C>T, c. 272A>G, c. 402A>C, c. 421G>T, c. 84-291A>G and c. 317C>T were classified as likely pathogenic variants. A novel c. 289_290insCTT variant was classified as likely pathogenic (PM1+ PM2_Supporting+ PM3+ PP3+ PP4). The two variants (c.478C>T and c. 665C>T) detected in the QDPR gene were both classified as variants of uncertain significance (PM1+ PM2_Supporting+ PP3+ PP4). Conclusion:Genetic testing has clarified the pathogenic variants in these BH4D patients, which has enabled timely and accurate clinical intervention and treatment, and provided a reference for genetic counseling and reproductive guidance for their families.

Objective:To explore the genetic basis for a Chinese pedigree affected with co-morbid Ornithine carbamoyl transferase deficiency (OTCD) and MECP2 duplication syndrome.Methods:A proband who was admitted to the Neonatal Intensive Care Unit of Gansu Provincial Maternal and Child Health Care Hospital on December 19, 2017 was selected as the study subject. High-throughput sequencing and multiplex ligation-dependent probe amplification (MLPA) were carried out for her pedigree, and short tandem repeat-based linkage analysis and chromosome copy number variation sequencing (CNV-seq) were used for the prenatal diagnosis.Results:The proband, a 3-day-old female, was found to harbor heterozygous deletion of exons 7-9 of the OTC gene. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the variant was classified as likely pathogenic (PVS1+ PM2_Supporting+ PP4). The proband was diagnosed with OTCD, which was in keeping with her acute encephalopathy and metabolic abnormalities (manifesting as hyperammonemia, decreased blood citrulline, and increased urine orotic acid). Prenatal diagnosis was carried out for the subsequent pregnancy. The fetus did not harbor the exons 7-9 deletion of the OTC gene, but was found to carry a duplication in Xq28 region (which encompassed the whole region of MECP2 duplication syndrome) and was positive for the SRY sequence. The same duplication was also found in the proband and her mother. Considering the possible existence of X-chromosome inactivation, the proband was diagnosed with two X-linked recessive disorders including OTCD and MECP2 duplication syndrome, and the fetus was determined as a male affected with the MECP2 duplication syndrome. Conclusion:Discoveries of the pathogenic variants underlying the OTCD and MECP2 duplication syndrome have enabled clinical intervention, treatment, genetic counseling and prenatal diagnosis for this pedigree.

Objective:To explore the genetic basis for a patient with unexplained developmental delay and special facial features.Methods:A male patient admitted to the Maternal and Child Health Care Hospital of Gansu Province on May 27, 2021 due to infertility was selected as the study subject. Clinical data of the patient was collected, and genomic DNA was extracted from peripheral blood samples from the patient and his parents. Whole exome sequencing (WES) was carried out, and candidate variant was verified by Sanger sequencing.Results:The patient was found to harbor a 2.54 Mb deletion in 1p36.33p36.32 and a heterozygous c. 1123G>C (p.E375Q) variant of the CHD3 gene, neither of which was detected in his parents. Conclusion:The patient was diagnosed with Snijders Blok-Campeau syndrome in conjunct with 1p36 deletion syndrome, which has enabled genetic counseling for his family.

Objective:To explore the genetic basis for a patient with autosomal dominant retinitis pigmentosa (RP).Methods:A male patient with RP treated at Gansu Provincial Maternal and Child Health Care Hospital in September 2019 was selected as the study subject. Clinical data was collected. Peripheral blood samples of the patient and his parents were subjected to whole exome sequencing (WES). Candidate variant was validated by Sanger sequencing and bioinformatic analysis.Results:The patient, a 29-year-old male, developed night blindness, amblyopia, visual field defects and optic disc abnormalities since childhood. Gene sequencing revealed that he has harbored a heterozygous c. 942G>C (p.Lys314Asn) variant of the IMPDH1 gene, which was inherited from his mother, whilst his father was of the wild type. Based on the guidelines from the American College of Medical Genetics and Genomics, the c. 942G>C variant was predicted as likely pathogenic (PM1+ PM2_Supporting+ PP3+ PP1). Conclusion:The c. 942G>C (p.Lys314Asn) variant in the IMPDH1 gene probably underlay the RP in this patient.

Objective:To analyze the clinical phenotype and genotypes of two children with Carnitine-acylcarnitine translocase deficiency (CACTD).Methods:Two children diagnosed with CACTD at the Gansu Provincial Maternal and Child Health Care Hospital respectively on January 3 and November 19, 2018 were selected as the study subjects. Trio-whole exome sequencing (trio-WES) was carried out, and candidate variants were validated through Sanger sequencing and pathogenicity analysis.Results:Both children were males and had manifested mainly with hypoglycemia. Trio-WES and Sanger sequencing showed that child 1 had harbored compound heterozygous variants of the SLC25A20 gene, namely c. 49G>C (p.Gly17Arg) and c. 106-2A>G, which were inherited from his father and mother, respectively. Child 2 had harbored homozygous c. 199-10T>G variants of the SLC25A20 gene, which were inherited from both of his parents. Among these, the c. 106-2A>G and c. 49G>C variants were unreported previously. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the c. 49G>C (p.Gly17Arg), c. 106-2A>G, and c. 199-10T>G variants were classified as likely pathogenic (PM2_supporting+ PP3+ PM3_strong+ PP4), pathogenic (PVS1+ PM2_supporting+ PM5+ PP3), and pathogenic (PVS1+ PM2_supporting+ PP3+ PP5), respectively. Conclusion:Combined with their clinical phenotype and genetic analysis, both children were diagnosed with CACTD. Above finding has provided a basis for their treatment as well as genetic counseling and prenatal diagnosis for their families.

Objective:To explore the genetic characteristics of a child with comorbid 16p11.2 microdeletion syndrome and Rett syndrome (RTT).Methods:A male infant who was admitted to Gansu Provincial Maternity and Child Health Care Hospital in May 2020 was selected as the study subject. Clinical data of the infant was collected. Genomic DNA was extracted from peripheral blood samples from the infant and his parents, and subjected to whole exome sequencing (WES). Candidate variant was verified by Sanger sequencing.Result:The patient, a 4-day-old male infant, had presented with poor response, poor intake, feeding difficulties, and deceased at 8 months after birth. WES revealed that he has harbored a 0.643 Mb deletion in the 16p11.2 region, which encompassed key genes of the 16p11.2 microdeletion syndrome such as ALDOA, CORO1A, KIFF22, PRRT2 and TBX6. His father has carried the same deletion, but was phenotypically normal. The deletion was predicted to be pathogenic. The child was also found to harbor a maternally derived c. 763C>T (p.R255X) hemizygous variant of the MECP2 gene, which was also predicted to be pathogenic (PVS1+ PS4+ PM2_Supporting). Conclusion:The 16p11.2 deletion and the MECP2: c.763C>T (p.R255X) variant probably underlay the pathogenesis in this infant.

Objective To study the effects of dual-hemispheric transcranial direct current stimulation(Dual-tDCS)on upper limb motor function in chronic-phase stroke patients to provide theoretical references for neural mechanisms-based treatment of upper limb dysfunction.Methods Totally 24 chronic-phase stroke patients with upper limb motor dysfunction were selected from some hospital and divided into an experimental group(n=13)and a control group(n=11)the random number table.The control group was treated with tDCS pseudo-stimulation combined with conventional rehabilitation,while the experimental group was given with Dual-tDCS combined with conventional rehabilitation.The patient activities were assessed before and after treatment with Fugl-Meyer assessment upper limb scale(FMA-UL)and activities of daily living(ADL)scale.The changes of primary motor cortex(M1 area)and whole brain functional connectivity(FC)were compared before and after treatment.SPSS 24.0 statistical software was used for data analysis.Results After treatment,the two groups both had the FAM-UL and ADL scores increased significantly,and the experimental group had the scores statistically higher than those of the control group,and the differences were all statistically significant(P＜0.05).In the control group,the analysis on M1 area and whole brain FC after treatment indicated the FC decreased from M1 area at the unaffected side to midoccipital gyrus at the affected side and lingual gyrus and healthy angular gyrus at the unaffected side;there were no brain areas with changed FC found(P＜0.01).In the experimental group,the FC was lowered from M1 area at the unaffected side to cerebellum and cerebellar vermis at the unaffected side,while raised to precentral gyrus at the affected side(P＜0.01);the FC ascended from M1 area at the affected side to cerebellum and middle temporal gyrus at the affected side,while declined to precentral gyrus at the unaffected side(P＜0.01).Conclusion The neuromodulatory effect of Dual-tDCS on the brain improves FC in motor and non-motor-related brain areas in chronic-phase stroke patients,and may contribute to rehabilitation of upper limb motor dysfunction in chronic-phase stroke.[Chinese Medical Equipment Journal,2024,45(2):67-73]

Objective To perform genetic analysis in a family line of a pregnant couple with autosomal reces-sive non-syndromic deafness in order to identify its possible genetic etiology and provide prenatal diagnosis.Methods Whole-exome sequencing(WES)was used to analyze the genes of the proband,and Sanger sequencing was used to verify the suspected pathogenic loci.Prenatal genetic diagnosis was performed after amniotic fluid collection at 18 weeks of pregnancy.Results Autosomal recessive deafness type 3 related gene MYO15A c.10419_10423delCAGCT/c.10294_10308delCCTTGCATCCTTGCC compound heterozygous variant was found in the wife.A compound heterozygous variant of autosomal recessive deafness type 77-related gene LOXHD1:c.6388C＞T/ex-on 33-38 del.Maternal MYO15A c.10294_10308del CCTTGCATCCTTGCC heterozygous variant were detected in the husband and paternal LOXHD1 exon 33-38 del heterozygous variant were detected in the fetus.At the same time,the paternal CDH23 c.6693delT heterozygous mutation and the maternal PCDH15 c.5048_5051dupAGAA heterozygous mutation were detected in the fetus.These two heterozygous mutations lead to the possibility of the fe-tus suffering from ID/F Usher syndrome.Conclusion The deafness of the couple is caused by two different deaf gene mutations,and the probability of the fetus having the same deafness as the couple is very low.However,the fetus has a high possibility of having deafness caused by two gene mutations.Therefore,deafness caused by two gene mutations should be paid attention to in the prenatal diagnosis of families with both deaf parents.