Changes in Body Mass Index, Leptin, and Leptin Receptor Polymorphisms and Breast Cancer Risk
DNA AND CELL BIOLOGY
Authors: Liu, Chun-Rong; Li, Qin; Hou, Can; Li, Hui; Shuai, Ping; Zhao, Min; Zhong, Xiao-Rong; Xu, Zhu-Ping; Li, Jia-Yuan
Abstract
Obesity is a strong risk factor for breast cancer. The polymorphisms of leptin (LEP) and leptin receptor (LEPR) may be associated with breast cancer by regulator of adipose tissue mass and tumor cell growth. A total of 794 cases and 805 matched controls were sequentially enrolled. Time-of-flight mass spectrometry was used to determine the LEPrs7799039, LEPRrs1137100, and LEPRrs1137101 genotypes for each participant. Associations between polymorphisms of these genes, change in body mass index (BMI), and breast cancer risk were assessed by unconditional multivariable logistic regression models. The unconditional logistic regression model showed that persistent overweight (BMI 24kg/m(2)) over the preceding 10 years was associated with increased breast cancer risk in premenopausal women (odds ratio [OR]=1.67, 95% confidence interval [CI]: 1.19-2.35). No associations between LEPrs7799039, LEPRrs1137100, or LEPRrs1137101 polymorphisms alone and breast cancer risk were found. Persistent overweight over the preceding 10 years and carrying the LEPrs7799039 AA genotype together increased breast cancer risk in premenopausal women (ORadj=2.00, 95% CI: 1.26-3.16). Persistent overweight over the preceding 10 years and carrying the LEPRrs1137100 GG genotype increased breast cancer risk in premenopausal women (ORadj=1.68, 95% CI: 1.06-2.68). In premenopausal women, persistent overweight (BMI 24kg/m(2)) over the preceding 10 years increases breast cancer risk. Persistent overweight along with LEPrs7799039 AA or LEPRrs1137100 GG genotypes synergistically increase risk of breast cancer among premenopausal women.
Genetic Causes of Severe Childhood Obesity: A Remarkably High Prevalence in an Inbred Population of Pakistan
DIABETES
Authors: Saeed, Sadia; Arslan, Muhammad; Manzoor, Jaida; Din, Sadia M.; Janjua, Qasim M.; Ayesha, Hina; Ain, Qura-tul; Inam, Laraib; Lobbens, Stephane; Vaillant, Emmanuel; Durand, Emmanuelle; Derhourhi, Mehdi; Amanzougarene, Souhila; Badreddine, Alaa; Berberian, Lionel; Gaget, Stefan; Khan, Waqas I.; Butt, Taeed A.; Bonnefond, Amelie; Froguel, Philippe
Abstract
Monogenic forms of obesity have been identified in <= 10% of severely obese European patients. However, the overall spectrum of deleterious variants (point mutations and structural variants) responsible for childhood severe obesity remains elusive. In this study, we genetically screened 225 severely obese children from consanguineous Pakistani families through a combination of techniques, including an in-house-developed augmented whole-exome sequencing method (CoDE-seq) that enables simultaneous detection of whole-exome copy number variations (CNVs) and point mutations in coding regions. We identified 110 (49%) probands carrying 55 different pathogenic point mutations and CNVs in 13 genes/loci responsible for nonsyndromic and syndromic monofactorial obesity. CoDE-seq also identified 28 rare or novel CNVs associated with intellectual disability in 22 additional obese subjects (10%). Additionally, we highlight variants in candidate genes for obesity warranting further investigation. Altogether, 59% of cases in the studied cohort are likely to have a discrete genetic cause, with 13% of these as a result of CNVs, demonstrating a remarkably higher prevalence of monofactorial obesity than hitherto reported and a plausible overlapping of obesity and intellectual disabilities in several cases. Finally, inbred populations with a high prevalence of obesity provide unique, genetically enriched material in the quest of new genes/variants influencing energy balance.