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Journal of Endocrinological... Jun 2023Parathyroid diseases are related to parathyroid hormone (PTH) dysregulation by parathyroid cells or alteration of PTH function. They include hyperparathyroidism (PTH... (Review)
Review
PURPOSE
Parathyroid diseases are related to parathyroid hormone (PTH) dysregulation by parathyroid cells or alteration of PTH function. They include hyperparathyroidism (PTH excess), hypoparathyroidism (PTH deficiency) and pseudohypoparathyroidism (PTH resistance). Little is known about correlation between parathyroid diseases and metabolic syndrome (MetS).
METHODS
An electronic-based search using PubMed was performed until October 2022 and articles were selected based on relevance of title, abstract, English language and publication in peer-reviewed journals.
RESULTS
Possible association between PTH alterations and the diverse manifestation of MetS have been proposed and it could be supposed that MetS may negatively influence parathyroid diseases. Available data show significant association for hyperparathyroidism and pseudohypoparathyroidism.
CONCLUSIONS
This review highlights the possible implications between MetS and parathyroid diseases. Given the increasing MetS global prevalence and the higher parathyroid diseases awareness and diagnosis, it may be interesting to further explore the possible role of alterations in parathyroid homeostasis in the development of MetS components with dedicated prospective studies.
Topics: Humans; Metabolic Syndrome; Prospective Studies; Parathyroid Diseases; Parathyroid Hormone; Hypoparathyroidism; Pseudohypoparathyroidism; Hyperparathyroidism
PubMed: 36773188
DOI: 10.1007/s40618-023-02018-2 -
Current Osteoporosis Reports Jun 2015The GNAS complex locus encodes the alpha-subunit of the stimulatory G protein (Gsα), a ubiquitous signaling protein mediating the actions of many hormones,... (Review)
Review
The GNAS complex locus encodes the alpha-subunit of the stimulatory G protein (Gsα), a ubiquitous signaling protein mediating the actions of many hormones, neurotransmitters, and paracrine/autocrine factors via generation of the second messenger cAMP. GNAS gives rise to other gene products, most of which exhibit exclusively monoallelic expression. In contrast, Gsα is expressed biallelically in most tissues; however, paternal Gsα expression is silenced in a small number of tissues through as-yet-poorly understood mechanisms that involve differential methylation within GNAS. Gsα-coding GNAS mutations that lead to diminished Gsα expression and/or function result in Albright's hereditary osteodystrophy (AHO) with or without hormone resistance, i.e., pseudohypoparathyroidism type-Ia/Ic and pseudo-pseudohypoparathyroidism, respectively. Microdeletions that alter GNAS methylation and, thereby, diminish Gsα expression in tissues in which the paternal Gsα allele is normally silenced also cause hormone resistance, which occurs typically in the absence of AHO, a disorder termed pseudohypoparathyroidism type-Ib. Mutations of GNAS that cause constitutive Gsα signaling are found in patients with McCune-Albright syndrome, fibrous dysplasia of bone, and different endocrine and non-endocrine tumors. Clinical features of these diseases depend significantly on the parental allelic origin of the GNAS mutation, reflecting the tissue-specific paternal Gsα silencing. In this article, we review the pathogenesis and the phenotypes of these human diseases.
Topics: Bone Diseases; Chromogranins; Exons; Fibrous Dysplasia of Bone; GTP-Binding Protein alpha Subunits, Gs; Humans; Mutation; Pseudohypoparathyroidism
PubMed: 25851935
DOI: 10.1007/s11914-015-0268-x -
Frontiers in Endocrinology 2023is a complex locus characterized by multiple transcripts and an imprinting effect. It orchestrates a variety of physiological processes via numerous signaling pathways.... (Review)
Review
is a complex locus characterized by multiple transcripts and an imprinting effect. It orchestrates a variety of physiological processes via numerous signaling pathways. Human diseases associated with the gene encompass fibrous dysplasia (FD), Albright's Hereditary Osteodystrophy (AHO), parathyroid hormone(PTH) resistance, and Progressive Osseous Heteroplasia (POH), among others. To facilitate the study of the locus and its associated diseases, researchers have developed a range of mouse models. In this review, we will systematically explore the locus, its related signaling pathways, the bone diseases associated with it, and the mouse models pertinent to these bone diseases.
Topics: Animals; Mice; Humans; GTP-Binding Protein alpha Subunits, Gs; Chromogranins; Pseudohypoparathyroidism; Bone Diseases, Metabolic; Ossification, Heterotopic
PubMed: 37920253
DOI: 10.3389/fendo.2023.1255864 -
Bone Apr 2018GNAS is a complex imprinted gene encoding the alpha-subunit of the stimulatory heterotrimeric G protein (Gsα). GNAS gives rise to additional gene products that exhibit... (Review)
Review
GNAS is a complex imprinted gene encoding the alpha-subunit of the stimulatory heterotrimeric G protein (Gsα). GNAS gives rise to additional gene products that exhibit exclusively maternal or paternal expression, such as XLαs, a large variant of Gsα that shows exclusively paternal expression and is partly identical to the latter. Gsα itself is expressed biallelically in most tissues, although the expression occurs predominantly from the maternal allele in a small set of tissues, such as renal proximal tubules. Inactivating mutations in Gsα-coding GNAS exons are responsible for Albright's hereditary osteodystrophy (AHO), which refers to a constellation of physical and developmental disorders including obesity, short stature, brachydactyly, cognitive impairment, and heterotopic ossification. Patients with Gsα mutations can present with AHO in the presence or absence of end-organ resistance to multiple hormones including parathyroid hormone. Maternal Gsα mutations lead to AHO with hormone resistance (i.e. pseudohypoparathyroidism type-Ia), whereas paternal mutations cause AHO alone (i.e. pseudo-pseudohypoparathyroidism). Heterotopic ossification associated with AHO develops through intramembranous bone formation and is limited to dermis and subcutis. In rare cases carrying Gsα mutations, however, ossifications progress into deep connective tissue and skeletal muscle, a disorder termed progressive osseous heteroplasia (POH). Here I briefly review the genetic, clinical, and molecular aspects of these disorders caused by inactivating GNAS mutations, with particular emphasis on heterotopic ossification.
Topics: Animals; Chromogranins; Cyclic AMP; GTP-Binding Protein alpha Subunits, Gs; Humans; Mutation; Ossification, Heterotopic
PubMed: 28889026
DOI: 10.1016/j.bone.2017.09.002 -
Journal of Molecular Endocrinology Jan 2024Several human disorders are caused by genetic or epigenetic changes involving the GNAS locus on chromosome 20q13.3 that encodes the alpha-subunit of the stimulatory G... (Review)
Review
Several human disorders are caused by genetic or epigenetic changes involving the GNAS locus on chromosome 20q13.3 that encodes the alpha-subunit of the stimulatory G protein (Gsα) and several splice variants thereof. Thus, pseudohypoparathyroidism type Ia (PHP1A) is caused by heterozygous inactivating mutations involving the maternal GNAS exons 1-13 resulting in characteristic abnormalities referred to as Albright's hereditary osteodystrophy (AHO) that are associated with resistance to several agonist ligands, particularly to parathyroid hormone (PTH), thereby leading to hypocalcemia and hyperphosphatemia. GNAS mutations involving the paternal Gsα exons also cause most of these AHO features, but without evidence for hormonal resistance, hence the term pseudopseudohypoparathyroidism (PPHP). Autosomal dominant pseudohypoparathyroidism type Ib (PHP1B) due to maternal GNAS or STX16 mutations (deletions, duplications, insertions, and inversions) is associated with epigenetic changes at one or several differentially methylated regions (DMRs) within GNAS. Unlike the inactivating Gsα mutations that cause PHP1A and PPHP, hormonal resistance is caused in all PHP1B variants by impaired Gsα expression due to loss of methylation at GNAS exon A/B, which can be associated in some familial cases with epigenetic changes at the other maternal GNAS DMRs. The genetic defect(s) responsible for sporadic PHP1B, the most frequent variant of this disorder, remain(s) unknown for the majority of patients. However, characteristic epigenetic GNAS changes can be readily detected that include a gain of methylation at the neuroendocrine secretory protein (NESP) DMR. Multiple genetic or epigenetic GNAS abnormalities can thus impair Gsα function or expression, consequently leading to inadequate cAMP-dependent signaling events downstream of various Gsα-coupled receptors.
Topics: Humans; Chromogranins; Pseudohypoparathyroidism; GTP-Binding Protein alpha Subunits, Gs; Epigenesis, Genetic; DNA Methylation
PubMed: 37965945
DOI: 10.1530/JME-23-0104 -
Current Opinion in Endocrinology,... Feb 2017To provide readers with a review of contemporary literature describing the evolving understanding of the pseudohypoparathyroidism type 1A (PHP1A) phenotype. (Review)
Review
PURPOSE OF REVIEW
To provide readers with a review of contemporary literature describing the evolving understanding of the pseudohypoparathyroidism type 1A (PHP1A) phenotype.
RECENT FINDINGS
The classic features of PHP1A include multihormone resistance and the Albright Hereditary Osteodystrophy phenotype (round facies, short stature, subcutaneous ossifications, brachydactyly, and early-onset obesity. Obesity may be because of a decrease in resting energy expenditure because most patients do not report significant hyperphagia. Patients with PHP1A have an increased risk of type 2 diabetes. In addition to brachydactyly and short stature, orthopedic complications can include spinal stenosis and carpal tunnel syndrome. Hearing loss, both sensorineural and conductive, has been reported in PHP1A. In addition, ear-nose-throat findings include decreased olfaction and frequent otitis media requiring tympanostomy tubes. Sleep apnea was shown to be 4.4-fold more common in children with PHP1A compared with other obese children; furthermore, asthma-like symptoms have been reported. These new findings are likely multifactorial and further research is needed to better understand these nonclassic features of PHP1A.
SUMMARY
Along with the Albright Hereditary Osteodystrophy phenotype and hormone resistance, patients with PHP1A may have additional skeletal, metabolic, ear-nose-throat, and pulmonary complications. Understanding these nonclassic features will help improve clinical care of patients with PHP1A.
Topics: Diabetes Mellitus, Type 2; Drug Resistance; Energy Metabolism; Hormones; Humans; Obesity; Phenotype; Pseudohypoparathyroidism
PubMed: 27875418
DOI: 10.1097/MED.0000000000000306 -
Journal of the Endocrine Society Dec 2021Pseudohypoparathyroidism (PHP) is a rare hormone resistance syndrome caused by mutations in . This cross-sectional study investigated whether PHP patients with...
Pseudohypoparathyroidism (PHP) is a rare hormone resistance syndrome caused by mutations in . This cross-sectional study investigated whether PHP patients with parathyroid hormone (PTH), thyrotropin (thyroid stimulating hormone; TSH), and free thyroxine (T4) levels at goal required higher doses of levothyroxine and calcitriol than recommended by current guidelines to overcome mineral ion abnormalities due to hormone resistance. Baseline demographic and clinical data of participants enrolled in PHP research studies between 2012-2021 were collected via retrospective chart review. Longitudinally, data were recorded at a maximum frequency of once a year starting at 1 year of age. The PTH at goal (PAG) group was defined as PTH < 150 pg/mL and calcium ≥ 8.4 mg/dL, and the TSH and free T4 at goal (TAG) group was defined as TSH < 5 mIU/L and free T4 ≥ 0.8 ng/dL. The PAG group (n = 74) was prescribed higher calcitriol doses than the PTH not at goal (PNAG) group (n = 50) (0.9 ± 1.1 vs 0.5 ± 0.9 mcg/day, = 0.04) and 21% of individual patients were prescribed ≥ 1.5 mcg of calcitriol daily. This remained true after normalization for body weight (0.013 ± 0.015 vs 0.0067 ± 0.0095 mcg/kg/day, = 0.008). There was no statistically significant difference in levothyroxine dosing between the TAG group (n = 122) and TSH and free T4 not at goal (TNAG) group (n = 45) when normalized for weight (2.0 ± 0.7 vs 1.8 ± 0.7 mcg/kg/day, = 0.2). More than one-third of patients with PHP had PTH levels not at goal and some patients required calcitriol doses ≥ 1.5 mcg/day to meet current treatment goals.
PubMed: 34765856
DOI: 10.1210/jendso/bvab161