Methylation Defect in Imprinted Genes Detected in Patients with an Albright's Hereditary Osteodystrophy Like Phenotype and Platelet Gs Hypofunction

Pseudohypoparathyroidism (PHP) indicates a group of heterogeneous disorders whose common feature is represented by impaired signaling of hormones that activate Gsalpha, encoded by the imprinted GNAS gene. PHP-Ib patients have isolated Parathormone (PTH) resistance and GNAS epigenetic defects while PHP-Ia cases present with hormone resistance and characteristic features jointly termed as Albright's Hereditary Osteodystrophy (AHO) due to maternally inherited GNAS mutations or similar epigenetic defects as found for PHP-Ib. Pseudopseudohypoparathyroidism (PPHP) patients with an AHO phenotype and no hormone resistance and progressive osseous heteroplasia (POH) cases have inactivating paternally inherited GNAS mutations.We here describe 17 subjects with an AHO-like phenotype that could be compatible with having PPHP but none of them carried Gsalpha mutations. Functional platelet studies however showed an obvious Gs hypofunction in the 13 patients that were available for testing. Methylation for the three differentially methylated GNAS regions was quantified via the Sequenom EpiTYPER. Patients showed significant hypermethylation of the XL amplicon compared to controls (36 ± 3 vs. 29 ± 3%; p<0.001); a pattern that is reversed to XL hypomethylation found in PHPIb. Interestingly, XL hypermethylation was associated with reduced XLalphaS protein levels in the patients' platelets. Methylation for NESP and ExonA/B was significantly different for some but not all patients, though most patients have site-specific CpG methylation abnormalities in these amplicons. Since some AHO features are present in other imprinting disorders, the methylation of IGF2, H19, SNURF and GRB10 was quantified. Surprisingly, significant IGF2 hypermethylation (20 ± 10 vs. 14 ± 7%; p<0.05) and SNURF hypomethylation (23 ± 6 vs. 32 6%; p<0.001) was found in patients vs. controls, while H19 and GRB10 methylation was normal.In conclusion, this is the first report of methylation defects including GNAS in patients with an AHO-like phenotype without endocrinological abnormalities. Additional studies are still needed to correlate the methylation defect with the clinical phenotype

No association of anti-osteoporosis drugs with COVID-19-related outcomes in women: a nationwide cohort study

This study was performed to evaluate whether the use of drugs in the treatment of osteoporosis in women is associated with COVID-19 outcomes. The results showed that the risk of hospitalization, intensive care unit admission, and mortality was not altered in individuals taking anti-osteoporosis drugs, suggesting no safety issues during a COVID-19 infection. Introduction Whether patients with COVID-19 receiving anti-osteoporosis drugs have lower risk of worse outcomes has not been reported yet. The aim of this study was to evaluate the association of anti-osteoporosis drug use with COVID-19 outcomes in women. Methods Data obtained from a nationwide, multicenter, retrospective cohort of patients diagnosed with COVID-19 from March 11th to May 30th, 2020 was retrieved from the Turkish Ministry of Health Database. Women 50 years or older with confirmed COVID-19 who were receiving anti-osteoporosis drugs were compared with a 1:1 propensity score-matched COVID-19 positive women who were not receiving these drugs. The primary outcomes were hospitalization, ICU (intensive care unit) admission, and mortality. Results A total of 1997 women on anti-osteoporosis drugs and 1997 control patients were analyzed. In the treatment group, 1787 (89.5%) women were receiving bisphosphonates, 197 (9.9%) denosumab, and 17 (0.9%) teriparatide for the last 12 months. Hospitalization and mortality rates were similar between the treatment and control groups. ICU admission rate was lower in the treatment group (23.0% vs 27.0%, p = 0.013). However, multivariate analysis showed that anti-osteoporosis drug use was not an independent associate of any outcome. Hospitalization, ICU admission, and mortality rates were similar among bisphosphonate, denosumab, or teriparatide users. Conclusion Results of this nationwide study showed that preexisting use of anti-osteoporosis drugs in women did not alter the COVID-19-related risk of hospitalization, ICU admission, and mortality. These results do not suggest discontinuation of these drugs during a COVID-19 infection

Very small deletions within the NESP55 gene in pseudohypoparathyroidism type 1b

Pseudohypoparathyroidism (PHP) is caused by reduced expression of genes within the GNAS cluster, resulting in parathormone resistance. The cluster contains multiple imprinted transcripts, including the stimulatory G protein α subunit (Gs-α) and NESP55 transcript preferentially expressed from the maternal allele, and the paternally expressed XLas, A/B and antisense transcripts. PHP1b can be caused by loss of imprinting affecting GNAS A/B alone (associated with STX16 deletion), or the entire GNAS cluster (associated with deletions of NESP55 in a minority of cases). We performed targeted genomic next-generation sequencing (NGS) of the GNAS cluster to seek variants and indels underlying PHP1b. Seven patients were sequenced by hybridisation-based capture and fourteen more by long-range PCR and transposon-mediated insertion and sequencing. A bioinformatic pipeline was developed for variant and indel detection. In one family with two affected siblings, and in a second family with a single affected individual, we detected maternally inherited deletions of 40 and 33 bp, respectively, within the deletion previously reported in rare families with PHP1b. All three affected individuals presented with atypically severe PHP1b; interestingly, the unaffected mother in one family had the detected deletion on her maternally inherited allele. Targeted NGS can reveal sequence changes undetectable by current diagnostic methods. Identification of genetic mutations underlying epigenetic changes can facilitate accurate diagnosis and counselling, and potentially highlight genetic elements critical for normal imprint settin