Influence of thyroid function on the fetal fraction during second trimester of pregnancy / 中华医学遗传学杂志

OBJECTIVE@#To assess the influence of thyroid function on the fetal fraction (FF) during the second trimester of pregnancy.@*METHODS@#A total of 1 861 pregnant women undergoing non-invasive prenatal testing (NIPT) and thyroxine function testing at 12 ~ 26 gestational weeks at the Affiliated Suzhou Hospital of Nanjing Medical University/Suzhou Municipal Hospital from January 2016 to December 2020 were selected as the study subjects. Univariate analysis and multivariate regression models were used to assess the correlation between free thyroxine 4 (FT4) levels and FF.@*RESULTS@#Univariate linear regression analysis indicated that the FF is correlated to the level of FT4 (b = 0.035, P < 0.001). The median fetal FF was 10.78% (IQR: 8.2%, 13.82%), and this has increased along with the level of FT4 from 10.58% at <= 12.0 pmol/L to 11.77% at > 16.0 pmol/L. After further adjustment of gestational age and body mass index (BMI), the FF showed an increase trend along with the increase of FT4 levels, and a trend test also showed a statistical significance (Ptrend < 0.001).@*CONCLUSION@#Maternal FF can be affected by the level of free thyroxine during the second trimester of pregnancy.

Identification of a novel NF1 mutation in a Chinese family affected with neurofibromatosis type I / 中华医学遗传学杂志

OBJECTIVE@#To explore the molecular basis for a Chinese family affected with neurofibromatosis type I.@*METHODS@#Peripheral blood samples were collected from the proband and his parents. Potential mutations of NF1 gene were screened by PCR and Sanger sequencing. Pathogenicity of candidate mutations was analyzed using Polyphen-2 and Provean software.@*RESULTS@#Two mutations of the NF1 gene, including c.702G>A (synonymous mutation) and c.1733T>G (missense mutation), were discovered in the proband. Neither mutation was found in his parents and 50 healthy controls. Bioinformatics analysis indicated that the c.1733T>G mutation (p.Leu578Arg) was probably damaging. The affected codon L578 is highly conserved across various species.@*CONCLUSION@#The c.1733T>C mutation of the NF1 gene probably underlies the neurofibromatosis type I in this family.