Genetic testing for hereditary hyperparathyroidism and familial hypocalciuric hypercalcaemia in a large UK cohort
CLINICAL ENDOCRINOLOGY
Authors: Mariathasan, Sashi; Andrews, Katrina A.; Thompson, Edward; Challis, Ben G.; Wilcox, Sarah; Pierce, Heather; Hale, Julia; Spiden, Sarah; Fuller, Gavin; Simpson, Helen L.; Fish, Brian; Jani, Piyush; Seetho, Ian; Armstrong, Ruth; Izatt, Louise; Joshi, Mamta; Velusamy, Anand; Park, Soo-Mi; Casey, Ruth T.
Abstract
Background Primary hyperparathyroidism (PHPTH) is a common endocrine disorder and an estimated 10% of cases are hereditary, related to syndromes including; multiple endocrine neoplasia (MEN) type 1, MEN type 4, MEN2A and hereditary hyperparathyroidism-jaw tumour syndrome. Establishing the underlying genetic cause for PHPTH allows for personalized and cost-effective management. Familial hypocalicuric hypercalcaemia (FHH) is a benign disorder of hypercalcaemia associated with an inappropriately low urinary calcium excretion, which is quantified by the calcium creatinine clearance ratio (CCCR). Recent NHS England National Genomic Test Directory testing criteria for familial hyperparathyroidism state testing patients presenting with PHPTH and CCCR > 0.02 presenting (i) <35 years of age, or (ii) <45y with one of (a) multiglandular disease, or (b) hyperplasia on histology, or (c) ossifying fibroma(s) of the maxilla and/ or mandible, or (d) a family history of unexplained PHPTH. The testing criterion for FHH is a CCCR MEN1, CDC73, CASR, CDKN1A, CDKN1B, CDKN2B, CDKN2C, RET, GCM2, GNA11, andAP2S1in NHS-accredited Regional Genetic laboratories. Aims of this study were to better define testing criteria for suspected hereditary PHPTH in a UK cohort. Results A total of 121 patients were included in this study (92 female) with a mean age of 41 years (SD 17). A pathogenic germline variant was identified in 16% (n = 19). A pathogenic variant was identified in the PHPTH genesCDC73in a single patient andMEN1in six patients (6% of total), in the FHH genes,CASRin 11 patients andAP2S1in a single paediatric case (10% of total). A variant of uncertain significance (VUS) was identified in eight patients (6%) but over the course of this study familial segregation studies and computational analysis enabled re-classification of four of the variants, with two VUS's in theCASRgene being upgraded to likely pathogenic variants. Age at diagnosis and multiglandular disease as sole risk factors were not predictive of a pathogenic germline variant in this cohort but a positive family history was strongly predictive (P = .0002). A significant difference in the mean calcium creatinine clearance ratio (CCCR) in those patients with an identifiedCASRpathogenic variant versus those without (P = .0001) was demonstrated in this study. Thirty-three patients were aged over 50 years and the diagnostic rate of a pathogenic variant was 15.1% in those patients >50 years of age compared to 15.9% in those 50 years and with a CCCR of <0.01, were diagnosed with a pathogenic variant inCASR. Conclusion Family history was the strongest predictor of hereditary PHPTH in this cohort. This study has highlighted the importance of re-evaluating VUS's in order to inform patient management and enable appropriate genetic counselling. Finally, this study has demonstrated the need to consider genetic testing for PHPTH in patients of any age, particularly those with additional risk factors.
Serum concentrations and testicular expressions of insulin-like peptide 3 and Anti-Mullerian hormone in normal and cryptorchid male horses
THERIOGENOLOGY
Authors: Tsogtgerel, Munkhtuul; Komyo, Nao; Murase, Harutaka; Hannan, M. A.; Watanabe, Kenichi; Ohtaki, Tadatoshi; Tsumagari, Shigehisa; Kawate, Noritoshi; Nambo, Yasuo
Abstract
Insulin-like peptide 3 (INSL3) is an important hormone for testicular descent during embryonic development and a factor for assessing functional status of Leydig cells of testes, but there is limited number of equine studies. Anti-Mullerian hormone (AMH) is a useful diagnostic marker for cryptorchidism in horses. This study aimed to compare serum concentrations and testicular expression intensity of INSL3 and AMH in intact and cryptorchid male horses. Serum INSL3 concentrations in intact (n = 9; mean +/- SEM, 19.9 +/- 5.9 ng/mL) and noncastrated unilateral cryptorchid (UC) male horses (n = 16; mean +/- SEM, 16.8 +/- 4.1 ng/mL) were higher compared with hemicastrated unilateral cryptorchid (HCUC) male horses (n = 9; mean +/- SEM, 3.8 +/- 0.7 ng/mL) (P < 0.05). And serum INSL3 in bilateral cryptorchid (BC) male horses (n = 4; 1.9 +/- 0.4; mean +/- SEM, ng/mL) were lower compared with intact male horses (P < 0.05). Serum AMH concentrations in BC male horses (n = 3; mean +/- SEM, 30.6 +/- 4.8 ng/mL) were higher compared with intact male horses (n = 5; mean +/- SEM, 12.2 +/- 3.9 ng/mL) (P < 0.05). Immunostaining of scrotal and cryptorchid testis showed that Sertoli cells were positive for AMH, and Leydig cells were positive for INSL3. Staining intensity of AMH was higher in cryptorchid testis than in scrotal testis (P < 0.05). Furthermore, AMH expression intensity was higher in abdominal testis than in inguinal testis (P < 0.05). Immunostaining intensity of INSL3 in the testis was positively correlated with serum INSL3 (r, 0.7; P < 0.01), seminiferous tubule area (r, 0.727; P < 0.01), and Johnsen score for spermatogenesis (r, 0.604; P < 0.05), whereas immunostaining intensity of AMH in the testis was negatively correlated with seminiferous tubule area (r,-0.814; P < 0.01) and Johnsen score for spermatogenesis (r,-0.807; P < 0.01). Our findings suggested that AMH is a good biomarker for diagnosing cryptorchidism in male horses, in addition to INSL3 values to assess the testis of intact and cryptorchid male horses. (C) 2020 Elsevier Inc. All rights reserved.