Severe early-onset obesity
Gene: KSR2
KSR2 is not associated with a phenotype on OMIM or Gene2Phenotype. PMID: 29273807 is a large study that combined data from approx. 720,000 individuals to find rare and low-frequency variants associated with BMI. A variant was found in KSR2. There was no details about this patient. Based on this data and the previous reviews, KSR2 has been left as a Amber gene until further cases/family case reports are available.Created: 15 Aug 2019, 2:02 p.m. | Last Modified: 11 Sep 2019, 9:17 a.m.
Panel Version: 1.22
Publications
Variants in this GENE are reported as part of current diagnostic practice
Comment on list classification: Gene added by expert reviewer. Not associated with a phenotype/disease in OMIM, Gene2Phenotype, Orphanet or HPO. PMID: 24209692 reported an enrichment of loss-of-function variants in KSR2 in severe, early-onset obesity (age of onset <10 years) recruited to the Genetics of Obesity Study cases versus controls (UK population-based study ELY), however the variants did not consistently co-segregate with severe obesity and they state that other genetic and/or environmental factors may modulate the phenotype. The KSR2 knockout mouse exhibits an obesity phenotype. A literature search revealed no other cases/family studies to provide further evidence for a Mendelian pattern of causation appropriate for reporting in a diagnostic setting, and therefore this gene should be kept red.Created: 17 Oct 2016, 9:01 a.m.
Comment on mode of inheritance: Most variants reported in PMID:24209692 were heterozygous, however some were found in homozygous state.Created: 17 Oct 2016, 9:01 a.m.
Gene: ksr2 has been classified as Amber List (Moderate Evidence).
Source Expert list was added to KSR2. Publications for gene KSR2 were changed from 24209692 - Study sequenced the KSR2 gene in 1770 individuals of mixed European descent with severe, early-onset obesity (age of onset <10 years) recruited to the Genetics of Obesity Study. Compared to 1536 control individuals from a large UK population-based study ELY. They report an enrichment of loss-of-function variants in KSR2 in cases versus controls, however these did not consistently co-segregate with severe obesity and they state that other genetic and/or environmental factors may modulate the phenotype. Some variants found in severely obese individuals were found in controls, and in publicly available exome data, though the authors argue that some of the controls were overweight/obese and for publicly available databases the phenotypic information are not available in order to rule out obesity in these individuals; 18719666 - This screen identified a novel body-fat phenotypes in KSR2 Knockout mice; 27561547 - ksr2(-/-) mice are normal size at birth but show a marked increase in FGF21 accompanied by reduced body mass, shortened body length, and reduced bone mineral density (BMD) and content (BMC) first evident during postnatal development; 24997067 - Relative to wild-type mice, ksr2(-/-) mice are small prior to weaning with normal glucose tolerance at 6 weeks of age, but demonstrate excess adiposity by 9 weeks and glucose intolerance by 12-14 weeks...The phenotype of C57BL/6 ksr2(-/-) mice, including obesity and obesity-related dysregulation of glucose homeostasis, recapitulates that of humans with KSR2 mutations, demonstrating the applicability of the C57BL/6 ksr2(-/-) mouse model to the study of the pathogenesis of human disease to 29273807
25/Oct/2016: Panel revised according to expert review and additional curation with internal discussion. Ready to be promoted to version 1.
Mode of inheritance for KSR2 was changed to BOTH monoallelic and biallelic, autosomal or pseudoautosomal
Publications for KSR2 were set to 24209692 - Study sequenced the KSR2 gene in 1770 individuals of mixed European descent with severe, early-onset obesity (age of onset <10 years) recruited to the Genetics of Obesity Study. Compared to 1536 control individuals from a large UK population-based study ELY. They report an enrichment of loss-of-function variants in KSR2 in cases versus controls, however these did not consistently co-segregate with severe obesity and they state that other genetic and/or environmental factors may modulate the phenotype. Some variants found in severely obese individuals were found in controls, and in publicly available exome data, though the authors argue that some of the controls were overweight/obese and for publicly available databases the phenotypic information are not available in order to rule out obesity in these individuals; 18719666 - This screen identified a novel body-fat phenotypes in KSR2 Knockout mice; 27561547 - ksr2(-/-) mice are normal size at birth but show a marked increase in FGF21 accompanied by reduced body mass, shortened body length, and reduced bone mineral density (BMD) and content (BMC) first evident during postnatal development; 24997067 - Relative to wild-type mice, ksr2(-/-) mice are small prior to weaning with normal glucose tolerance at 6 weeks of age, but demonstrate excess adiposity by 9 weeks and glucose intolerance by 12-14 weeks...The phenotype of C57BL/6 ksr2(-/-) mice, including obesity and obesity-related dysregulation of glucose homeostasis, recapitulates that of humans with KSR2 mutations, demonstrating the applicability of the C57BL/6 ksr2(-/-) mouse model to the study of the pathogenesis of human disease
Publications for KSR2 were set to 24209692; 18719666 - This screen identified a novel body-fat phenotypes in KSR2 Knockout mice; 27561547 - ksr2(-/-) mice are normal size at birth but show a marked increase in FGF21 accompanied by reduced body mass, shortened body length, and reduced bone mineral density (BMD) and content (BMC) first evident during postnatal development; 24997067 - Relative to wild-type mice, ksr2(-/-) mice are small prior to weaning with normal glucose tolerance at 6 weeks of age, but demonstrate excess adiposity by 9 weeks and glucose intolerance by 12-14 weeks...The phenotype of C57BL/6 ksr2(-/-) mice, including obesity and obesity-related dysregulation of glucose homeostasis, recapitulates that of humans with KSR2 mutations, demonstrating the applicability of the C57BL/6 ksr2(-/-) mouse model to the study of the pathogenesis of human disease
This gene has been classified as Red List (Low Evidence).
KSR2 was created by [email protected]
KSR2 was added to Significant early-onset obesity +/- other endocrine features and short staturepanel. Sources: Expert Review