Objective To investigate COL1A1 gene mutation by PCR-high resolution melting (PCR-HRM) and an-alyze the correlation between genotype and clinical phenotype in a child (proband) with osteogenesis imperfecta (OI). Methods The family history of OI pedigree along with the clinical data was collected. Blood samples from the proband and his family members, as well as 50 normal controls, were collected. The mutation of COL1A1 gene was screened using PCR-HRM and validated by the gene sequence. Results The detection of PCR-HRM showed the abnormal result of COL1A1 17 exon in proband with a lower melting temperature (Tm) value than that of normal controls by 0.4℃. There were signifi-cant differences in the standardization melting curve and the different melting curve between the proband and the normal controls. The sequencing result was c.1138G>A, which meant that cDNA of 1138 base G mutation into A. The mutations transformed the amino acid glycine into a serine at amino acid 380(P. Gly 380 Ser), which resulted in missense mutations. The proband’s father and grandmother had the same mutation of COL1A1 gene. The mutation was not found in the proband’s mother and normal controls. There was no report for such mutation in Chinese population. Pedigree analysis showed the fami-ly genetic characteristics of autosomal dominant inheritance. The proband was clinically diagnosed as OI type Ⅳwith more severe clinical phenotype. Conclusion PCR-HRM analysis is a new effective method for genetic screening of OI. COL1A1 mutation of c.1138G>A is a newly discovered mutation in Chinese population. Gly replaced inαhelical domain may lead to a more severe clinical phenotype.

OBJECTIVETo explore genetic mutations and clinical features of osteogenesis imperfecta type V.

METHODSClinical record of five patients (including one familial case) with osteogenesis imperfecta type V were retrospectively analyzed. Peripheral blood samples of the patients, one family member, as well as healthy controls were collected. Mutation of IFITM5 gene was identified by PCR amplification and Sanger sequencing.

RESULTSA heterozygous mutation (c.-14C>T) in the 5-UTR of the IFITM5 gene was identified in all of the patients and one mother. The clinical findings included frequent fractures and spine and/or extremities deformities, absence of dentinogenesis imperfecta, absence of hearing impairment, and blue sclera in 1 case. Radiographic findings revealed calcification of the interosseous membrane between the radius-ulna in all cases. Hyperplastic callus formation was found in 3 cases. Four had radial-head dislocation.

CONCLUSIONA single heterozygous mutation c.-14C>T was found in the 5-UTR of the IFITM5 gene in 5 patients with osteogensis imperfecta type V. The patients showed specific radiological features including calcification of interosseous membrane, hyperplastic callus formation, and radial-head dislocation.

Adolescent ; Adult ; Child ; Child, Preschool ; Female ; Humans ; Male ; Mutation ; Osteogenesis Imperfecta ; diagnostic imaging ; genetics ; Young Adult

OBJECTIVETo investigate mutation of COL1A1 gene and analyze the relationship between genotype and clinical phenotype in a family with osteogenesis imperfecta (OI).

METHODSThe family history of an OI pedigree, along with clinical data, was collected. Blood samples from the proband and his families, as well as 50 normal controls, were collected. Mutation of COL1A1 gene was screened using PCR-high resolution melting (PCR-HRM) and validated by sequencing.

RESULTSPCR HRM method showed an abnormal result in proband COL1A133_34 exons, which Tm was 87.7℃, in contrast to the normal control (wt) Tm of 87.9±0.06℃. There was a significant difference between the proband and the normal control with the standardization curve and the difference curves. DNA sequencing showed that Y9COL1A1 gene exons 33_34 has lost a C base (c.2321delC), which resulted in a frameshift mutation and caused an premature termination codon (UAA) at amino acid 334, i.e., p.Pro774LeufsX334 The father and grandfather of the proband, both suffered from OI, were verified to be heterozygous for the same mutation. The same mutation was not found in 50 normal controls. Database search confirmed this to be a novel mutation. Pedigree analysis suggested that it has an autosomal dominant inheritance. The proband and patients from the family were clinically diagnosed as OI type I.

CONCLUSIONThe study has identified a novel mutation of COL1A1 gene, c.2321delC. This frameshift mutation has caused a premature stop codon and reduced collagen type synthesis, characterized by a lighter OI clinical phenotype.

Adult ; Asian Continental Ancestry Group ; genetics ; Base Sequence ; Child ; Child, Preschool ; China ; Collagen Type I ; genetics ; Female ; Frameshift Mutation ; Humans ; Male ; Molecular Sequence Data ; Osteogenesis Imperfecta ; genetics ; Pedigree

【Objective】 To evaluate the performance of light initiated chemiluminescence assay in the detection of hepatitis c virus (HCV), human immunodeficiency virus (HIV) and Treponema pallidum (TP) antibodies. 【Methods】 According to Guidance on the Verification of Qualitative Measurement Procedures used in the Clinical Immunology(CNAS-GL038: 2019) and Guidance on the Verification of Quantitative Measurement Procedures used in the Clinical Chemistry(CNAS-GL037: 2019), the coincidence rate, detection limit, precision and critical value of the detection of HCV, HIV and TP antibodies by the automatic light initiated chemiluminescence assay system LICA500 were verified. 【Results】 The concordance rate of LICA500 and ELISA in HCV antibody and HIV antibody detection was 100%. In terms of syphilis antibody detection, the concordance rate with TPPA results was 95%. The detection limit test showed that the detection limits of LICA500 against HCV antibody, HIV antibody and TP antibody reached 0.04 NCU/mL, 0.5 NCU/mL and 0.25 NCU/mL, respectively, which were all higher than the manufacturer′s declared detection limits of 0.2 NCU/mL, 1 NCU/mL and 0.5 NCU/mL. The in-batch CV and total CV of LICA500 for HCV, HIV and TP antibodies were less than 10%. The C50 was verified by critical value experiment, and the positive results of HCV antibody, HIV antibody and TP antibody at the critical concentration accounted for 45%, 45% and 48%, respectively. The percentage of negative results for (critical concentration -20%) was 98%, and the percentage of positive results for (critical concentration + 20%) was 100%, indicating that the concentration range from (critical concentration -20%) to (critical concentration + 20%) was in the 95% range of this method. 【Conclusion】 The detection of HCV, HIV and TP antibodies by LICA500 has a high concordance rate with the current commonly used detection methods, suitable for rapid screening and batch examination before surgery and blood transfusion.