Rachel Freathy and colleagues report results of a large-scale genome-wide association study of birth weight. They identify four loci newly associated with this trait and find overlap between birth weight–associated loci and those influencing adult height and metabolism. Birth weight within the normal range is associated with a variety of adult-onset diseases, but the mechanisms behind these associations are poorly understood1. Previous genome-wide association studies of birth weight identified a variant in the ADCY5 gene associated both with birth weight and type 2 diabetes and a second variant, near CCNL1, with no obvious link to adult traits2. In an expanded genome-wide association meta-analysis and follow-up study of birth weight (of up to 69,308 individuals of European descent from 43 studies), we have now extended the number of loci associated at genome-wide significance to 7, accounting for a similar proportion of variance as maternal smoking. Five of the loci are known to be associated with other phenotypes: ADCY5 and CDKAL1 with type 2 diabetes, ADRB1 with adult blood pressure and HMGA2 and LCORL with adult height. Our findings highlight genetic links between fetal growth and postnatal growth and metabolism.

Background The indications for intestinal transplantation (ITx) are still debated. Knowing survival rates and causes of death on home parenteral nutrition (HPN) will improve decisions. Methods A prospective 5-year study compared 389 non-candidates (no indication, no contraindication) and 156 candidates (indication, no contraindication) for ITx. Indications were: HPN failure (liver failure; multiple episodes of catheter-related venous thrombosis or sepsis; severe dehydration), high-risk underlying disease (intra-abdominal desmoids; congenital mucosal disorders; ultra-short bowel), high morbidity intestinal failure. Causes of death were defined as: HPN-related, underlying disease, or other cause. Results The survival rate was 87% in non-candidates, 73% in candidates with HPN failure, 84% in those with high-risk underlying disease, 100% in those with high morbidity intestinal failure and 54%, in ITx recipients (one non-candidate and 21 candidates) (p2 years (p=0.006). In candidates, the death HRs were increased in those with desmoids (7.1; 95% CI 2.5 to 20.5; p=0.003) or liver failure (3.4; 95% CI 1.6 to 7.3; p=0.002) compared to non-candidates. In deceased candidates, the indications for ITx were the causes of death in 92% of those with desmoids or liver failure, and in 38% of those with other indications (p=0.041). In candidates with catheter-related complications or ultra-short bowel, the survival rate was 83% in those who remained on HPN and 78% after ITx (p=0.767). Conclusions HPN is confirmed as the primary treatment for intestinal failure. Desmoids and HPN-related liver failure constitute indications for life-saving ITx. Catheter-related complications and ultra-short bowel might be indications for pre-emptive/rehabilitative ITx. In the early years after commencing HPN a life-saving ITx could be required for some patients at higher risk of death from their underlying disease.