Obesity-Associated GNAS Mutations and the Melanocortin Pathway
| Autor: | Aliki Perdikari, Jacek Mokrosinski, Tabitha Randell, I. Sadaf Farooqi, Sharon Lim, Fleur Talbot, Rebecca Bounds, Melanie Kershaw, Deepthi Jyothish, Edson Mendes de Oliveira, Tim Cheetham, Antoinette McAulay, Vikram Ayinampudi, Elizabeth C Crowne, Inês Barroso, Peter T Clayton, Praveen Partha, Cristina Matei, Sanjay Gupta, Louise C Wilson, Elana Henning, Keogh Jm, Rachel Ahmed, Natalia Wasiluk |
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| Rok vydání: | 2021 |
| Předmět: |
musculoskeletal diseases
030213 general clinical medicine medicine.medical_specialty medicine.disease_cause Short stature Thyrotropin receptor 03 medical and health sciences 0302 clinical medicine Internal medicine GNAS complex locus Medicine Pseudohypoparathyroidism Exome sequencing 030304 developmental biology 0303 health sciences Mutation biology business.industry General Medicine medicine.disease 3. Good health Melanocortin 4 receptor Endocrinology biology.protein medicine.symptom Melanocortin business |
| Zdroj: | New England Journal of Medicine. 385:1581-1592 |
| ISSN: | 1533-4406 0028-4793 |
| Popis: | Background GNAS encodes the Gαs (stimulatory G-protein alpha subunit) protein, which mediates G protein-coupled receptor (GPCR) signaling. GNAS mutations cause developmental delay, short stature, and skeletal abnormalities in a syndrome called Albright's hereditary osteodystrophy. Because of imprinting, mutations on the maternal allele also cause obesity and hormone resistance (pseudohypoparathyroidism). Methods We performed exome sequencing and targeted resequencing in 2548 children who presented with severe obesity, and we unexpectedly identified 22 GNAS mutation carriers. We investigated whether the effect of GNAS mutations on melanocortin 4 receptor (MC4R) signaling explains the obesity and whether the variable clinical spectrum in patients might be explained by the results of molecular assays. Results Almost all GNAS mutations impaired MC4R signaling. A total of 6 of 11 patients who were 12 to 18 years of age had reduced growth. In these patients, mutations disrupted growth hormone-releasing hormone receptor signaling, but growth was unaffected in carriers of mutations that did not affect this signaling pathway (mean standard-deviation score for height, -0.90 vs. 0.75, respectively; P = 0.02). Only 1 of 10 patients who reached final height before or during the study had short stature. GNAS mutations that impaired thyrotropin receptor signaling were associated with developmental delay and with higher thyrotropin levels (mean [±SD], 8.4±4.7 mIU per liter) than those in 340 severely obese children who did not have GNAS mutations (3.9±2.6 mIU per liter; P = 0.004). Conclusions Because pathogenic mutations may manifest with obesity alone, screening of children with severe obesity for GNAS deficiency may allow early diagnosis, improving clinical outcomes, and melanocortin agonists may aid in weight loss. GNAS mutations that are identified by means of unbiased genetic testing differentially affect GPCR signaling pathways that contribute to clinical heterogeneity. Monogenic diseases are clinically more variable than their classic descriptions suggest. (Funded by Wellcome and others.). |
| Databáze: | OpenAIRE |
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