Analysis of cardiac troponin C gene TNNC1 c. G175C mutation in a Chinese pedigree with familial hypertrophic cardiomyopathy and the correlation between genotype and phenotype

Objective To investigate the genotype-phenotype correlation in Chinese familial hypertrophic cardiomyopathy(HCM)focusing on the cardiac troponic C gene TNNC1 c.G175C mutation.Methods All family members of a Chinese pedigree with hypertrophic cardiomyopathy admitted in Third People’s Hospital of Qingdao

Deletions in the genomes of fifteen inbred mouse lines and their possible implications for fat accumulation

Copy number variants (CNVs) are pieces of genomic DNA of 1000 base pairs or longer which occur in a given genome at a different frequency than in a reference genome. Their importance as a source for phenotypic variability has been recognized only in the last couple of years. Chromosomal deletions can be seen as a special case of CNVs where stretches of DNA are missing in certain lines when compared to the reference genome of the mouse line C57BL/6, for example. Based upon more than 8 million single nucleotide polymorphisms (SNPs) in the fifteen inbred mouse lines which were determined in a whole genome chip based resequencing project by Perlegen Sciences, we detected 20166 such long chromosomal deletions. They cover altogether between 4.4 million and 8.8 million base pairs, depending on the mouse line. Thus, their extent is comparable to that of SNPs. The chromosomal deletions were found by searching for clusters of missing values in the genotyping data by applying bioinformatics and biostatistical methods. In contrast to isolated missing values, clusters are likely the consequence of missing DNA probe rather than of a failed hybridization or deficient oligos. We analyzed these deletion sites in various ways. Twenty-two percent of these deletion sites overlap with exons; they could therefore affect a gene's functioning. The corresponding genes seem to exist in alternative forms, a phenomenon that reminds of the alternative forms of mRNA generated during gene splicing. We furthermore detected statistically significant association between hundreds of deletion sites and fat weight at the age of eight weeks.

Precision medicine via the integration of phenotype-genotype information in neonatal genome project

The explosion of next-generation sequencing(NGS)has enabled the widespread use of genomic data in precision medicine.Currently,several neonatal genome projects have emerged to explore the advantages of NGS to diagnose or screen for rare genetic disorders.These projects have made remarkable achievements,but still the genome data could be further explored with the assistance of phenotype collection.In contrast,longitudinal birth cohorts are great examples to record and apply phenotypic information in clinical studies starting at the neonatal period,especially the trajectory analyses for health development or disease progression.It is obvious that efficient integration of genotype and phenotype benefits not only the clinical management of rare genetic disorders but also the risk assessment of complex diseases.Here,we first summarize the recent neonatal genome projects as well as some longitudinal birth cohorts.Then,we propose two simplified strategies by integrating genotypic and phenotypic information in precision medicine based on current studies.Finally,research collaborations,sociological issues,and future perspectives are discussed.How to maximize neonatal genomic information to benefit the pediatric population remains an area in need of more research and effort.