Exome sequencing and subsequent association studies identify five amino acid-altering variants influencing human height.

Height is a highly heritable trait that involves multiple genetic loci. To identify causal variants that influence stature, we sequenced whole exomes of four children with idiopathic short stature. Ninety-five nonsynonymous single-nucleotide polymorphisms (nsSNPs) were selected as potential candidate variants. We performed association analysis in 740 cohort individuals and identified 11 nsSNPs in 10 loci (DIS3L2, ZBTB38, FAM154A, PTCH1, TSSC4, KIF18A, GPR133, ACAN, FAM59A, and NINL) associated with adult height (P < 0.05), including five novel loci. Of these, two nsSNPs (TSSC4 and KIF18A loci) were significant at P < 0.05 in the replication study (n = 1,000) and five (ZBTB38, FAM154A, TSSC4, KIF18A, and FAM59A loci) were significant at P < 0.01 in the combined analysis (n = 1,740). Together, the five nsSNPs accounted for approximately 2.5% of the height variation. This study demonstrated the utility of next-generation sequencing in identifying genetic variants and loci associated with complex traits.

Differences of urease activity and expression of associated genes according to gastric topography.

BACKGROUND: We hypothesize that pH difference between acid-secreting corpus and non-secreting antrum might influence the activity of H. pylori's urease and/or related genes. We therefore measured urease activity and the expression of amiE whose encoded protein that hydrolyzes short-chain amides to produce ammonia. MATERIALS AND METHODS: Fifty-four patients were recruited into this study. Each gastroscopic biopsy specimen collected from the antrum and body of each patient was immediately used to measure urease activity using serial changes of urease activity (ammonia levels) during 60 minutes. Probe specific for amiE was labeled with a biotin nick-translation kit and was used to detect expression of these genes (mRNA) in fresh-frozen gastroscopic biopsy specimens using fluorescent in situ hybridization (FISH). RESULTS: Urease activity at 60 minutes from the gastric antrum and body of all patients infected with H. pylori was 399.5 ± 490.5 and 837.9 ± 1038.9 µg/dL, respectively (p = .004). Urease activity in the antrum was correlated with H. pylori density. Urease activity or H. pylori density in the antrum was significantly correlated with chronic active inflammation; in contrast, this correlation was not found in the gastric body. The expression level of amiE was 1.5 times higher (p < .05) in the gastric body compared with the antrum. CONCLUSION: Topographically, the urease activity in body was much higher than in antrum. The expression level of amiE was higher in the gastric body compared with the antrum.

Exome sequencing identifies KIAA1377 and C5orf42 as susceptibility genes for monomelic amyotrophy.

Precise topographic localization, predominance in males mostly of Asian origin, and existence of some familial cases suggest a genetic background for monomelic amyotrophy. To identify susceptibility genes for monomelic amyotrophy, we performed whole-exome sequencing of four unrelated patients with monomelic amyotrophy and detected a total of 45 novel nonsynonymous single-nucleotide polymorphisms as unique variants to monomelic amyotrophy compared to control exomes. Genetic association analysis showed significant association with monomelic amyotrophy in the Gly668Ser variant of the KIAA1377 gene (odds ratio=4.62, P-value=0.0040) and the Pro1794Leu variant of the C5orf42 gene (odds ratio=4.63, P-value=0.0040). Moreover, the combination of two variants increased the risk of monomelic amyotrophy (P=1.4×10(-5), OR=61.69, 95% confidence interval=9.62-394.94, in case of combination of two heterozygotes). These data suggest that KIAA1377 and C5orf42 synergistically play a role as susceptibility genes for monomelic amyotrophy.