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Behavioural Neurology 2022To characterize the cerebral imaging and electroclinical features and investigate their etiological contributions to seizures in pseudoparathyroidism (PHP).
OBJECTIVE
To characterize the cerebral imaging and electroclinical features and investigate their etiological contributions to seizures in pseudoparathyroidism (PHP).
METHODS
The clinical symptoms, biochemical imaging by magnetic resonance imaging (MRI) and computed tomography (CT) tests, and electroencephalogram (EEG) manifestations of five PHP patients with seizures were retrospectively collected and analyzed.
RESULTS
Physical examination showed an average stature in cases 2~4 and short stature in cases 1 and 5. X-ray tests suggested ectopic calcification in four patients. The seizures in four cases were effectively controlled with antiseizure medicines (ASMs). Cerebral CT scans showed extensive brain calcifications in the bilateral basal ganglia (all five cases), cerebellum (cases 1, 3, and 5), thalamus (case 4), and cerebral cortex. Cerebral MRI showed short T1 signals mainly in the basal ganglia. EEG records revealed focal EEG abnormalities, including abnormal slow waves and epileptiform discharges, mainly over the temporal and frontal lobes. The brain areas with focal EEG abnormalities and calcification did not always coincide.
CONCLUSION
The seizures in PHP can be focal to bilateral tonic-clonic. ASMs are effective in epilepsy combined with PHP. Intracranial calcification is not a reliable etiological cause of epilepsy in PHP patients.
Topics: Electroencephalography; Epilepsy; Humans; Pseudohypoparathyroidism; Retrospective Studies; Seizures
PubMed: 35992960
DOI: 10.1155/2022/8710989 -
Orphanet Journal of Rare Diseases Nov 2023Pseudohypoparathyroidism type 1 (PHP1) is a rare disease featuring hypocalcemia and elevated PTH level. Though disturbed calcium and phosphorus metabolism under PTH...
BACKGROUND
Pseudohypoparathyroidism type 1 (PHP1) is a rare disease featuring hypocalcemia and elevated PTH level. Though disturbed calcium and phosphorus metabolism under PTH resistant have been widely studied, glucolipid metabolism abnormalities observed in PHP1 patients have received little attention. The aim of this research is to explore the glucolipid metabolism features in a rather large cohort of PHP1 patient. In the current study, PHP1 patients and primary hyperparathyroidism patients as well as normal control were recruited for the investigation. Glucolipid metabolic indices as well as the level of four adipokines were examined.
RESULTS
A total of 49 PHP1 patients, 64 PHPT patients and 30 healthy volunteers were enrolled. A trend of higher HOMA-β index was found in PHP1 patients than normal controls (median 97.08% vs 68.19%, p = 0.060). Both the PHP1 and PHPT group presented with significantly lower TNFα level compared to normal controls (average 10.74 pg/ml and 12.53 pg/ml vs 15.47 pg/ml, p = 0.002 and 0.041, respectively). FGF21 level was significantly higher in PHPT group than in PHP1 group (median 255.74 pg/ml vs 167.46 pg/ml, p = 0.019). No significant difference in glucolipid metabolic indices and adipokines was found between PHP1A or PHP1B patients and normal controls, while overweight/obese PHP1 patients tended to have higher leptin than normal-BMI cases (p = 0.055). Multiple linear regression analysis showed BMI rather than PTH or HOMA-IR to be an independent variable of leptin in PHP1.
CONCLUSION
Metabolic stress given upon especially overweight PHP1 patients may resulted in possible β-cell compensation. Elevated TNFα may be related with hyper-PTH level regardless of calcium level.
Topics: Humans; Calcium; Leptin; Adipokines; Tumor Necrosis Factor-alpha; Overweight; Pseudohypoparathyroidism
PubMed: 38017461
DOI: 10.1186/s13023-023-02979-w -
Diabetes, Metabolic Syndrome and... 2024Pseudohypoparathyroidism (PHP) is a rare genetic disease characterized by hypocalcemia, hyperphosphatemia, and elevated parathyroid hormone (PTH) in serum. Here, we...
Pseudohypoparathyroidism (PHP) is a rare genetic disease characterized by hypocalcemia, hyperphosphatemia, and elevated parathyroid hormone (PTH) in serum. Here, we report a case of a patient with pseudohypoparathyroidism type IB (PHPIB) and subclinical hypothyroidism, analyze the clinical and genetic data of his family members, review the relevant literature, and classify and discuss the pathogenesis and clinical characteristics of each subtype. Finally, we discuss the treatment approach to improve clinicians' understanding of the disease.
PubMed: 38765469
DOI: 10.2147/DMSO.S458405 -
Medical Archives (Sarajevo, Bosnia and... Feb 2023Hypothyroidism is a manifestation of multi-hormonal resistance in pseudohypoparathyroidism type Ia (PHP Ia). (Review)
Review
BACKGROUND
Hypothyroidism is a manifestation of multi-hormonal resistance in pseudohypoparathyroidism type Ia (PHP Ia).
OBJECTIVE
The aim of this article was to present 9 months old male patient as case of congenital hypothyroidism.
CASE REPORT
We describe a 9 months old male diagnosed with congenital hypothyroidism at age 1.5 month, who developed later (at age 5 months) cyanotic attack associated with hypocalcaemia, hyperphosphatemia, and hyperparathyroidism, patient had typical characters of AHO, so the diagnosis of Pseudohypoparathyroidism 1a associated with resistance (TSH) was established.
CONCLUSION
Children diagnosed with PHP 1a should be further evaluated for associated resistance endocrinopathies. The literature on pseudohypoparathyroidism is reviewed with special emphasis on the misdiagnosis with congenital hypothyroidism.
Topics: Humans; Infant; Male; Chromogranins; Congenital Hypothyroidism; Diagnostic Errors; GTP-Binding Protein alpha Subunits, Gs; Pseudohypoparathyroidism
PubMed: 36923733
DOI: 10.5455/medarh.2023.77.70-73 -
Journal of Bone and Mineral Research :... Oct 2022Loss of methylation (LOM) at GNAS-A/B:TSS-differentially methylated regions (DMRs) in the GNAS locus is observed in pseudohypoparathyroidism type 1B (PHP1B). Many PHP1B...
Loss of methylation (LOM) at GNAS-A/B:TSS-differentially methylated regions (DMRs) in the GNAS locus is observed in pseudohypoparathyroidism type 1B (PHP1B). Many PHP1B cases are sporadic, but autosomal dominant-PHP1B has a deletion involving NESP55 expressed from the maternal allele or STX16 located upstream of the GNAS locus on the maternal allele. We report the possible first familial PHP1B cases with retrotransposon insertion in the GNAS locus on the maternal allele. To our knowledge, they are the possible first cases with imprinting disorders caused by retrotransposon insertion. The two sibling cases experienced tetany and/or cramps from school age and had hypocalcemia and an increased serum intact parathyroid hormone (PTH) level together with overweight, round face, and normal intellectual levels. Methylation analysis for DMRs in the GNAS locus showed only LOM of the GNAS-A/B:TSS-DMR. Copy number abnormalities at STX16 and the GNAS locus were not detected by array comparative genomic hybridization. Whole-genome sequencing and Sanger sequencing revealed an approximately 1000-bp SVA retrotransposon insertion upstream of the first exon of A/B on the GNAS locus in these siblings. Whole-genome methylome analysis by Enzymatic Methyl-Seq in the siblings showed normal methylation status in the region surrounding the insertion site and mild LOM of the GNAS-A/B:TSS-DMR. We conducted transcriptome analysis using mRNA from skin fibroblasts and induced pluripotent stem cells (iPSCs) derived from the siblings and detected no aberrant NESP55 transcripts. Quantitative reverse-transcriptase PCR (qRT-PCR) analysis in skin fibroblasts showed increased A/B expression in the patients and no NESP55 expression, even in a control. qRT-PCR analysis in iPSCs showed decreased NESP55 expression with normal methylation status of the GNAS-NESP:TSS-DMR in the patients. The retrotransposon insertion in the siblings likely caused decreased NESP55 expression that could lead to increased A/B expression via LOM of the GNAS-A/B:TSS-DMR, subsequent reduced Gsα expression, and finally, PHP1B development. © 2022 American Society for Bone and Mineral Research (ASBMR).
Topics: Humans; Retroelements; Chromogranins; Comparative Genomic Hybridization; Pseudohypoparathyroidism; GTP-Binding Protein alpha Subunits, Gs; RNA, Messenger; Parathyroid Hormone; DNA-Directed RNA Polymerases; DNA Methylation
PubMed: 35859320
DOI: 10.1002/jbmr.4652 -
Clinical Epigenetics May 2022Beckwith-Wiedemann syndrome (BWS) and Pseudohypoparathyroidism type 1B (PHP1B) are imprinting disorders (ID) caused by deregulation of the imprinted gene clusters...
Novel genetic variants of KHDC3L and other members of the subcortical maternal complex associated with Beckwith-Wiedemann syndrome or Pseudohypoparathyroidism 1B and multi-locus imprinting disturbances.
BACKGROUND
Beckwith-Wiedemann syndrome (BWS) and Pseudohypoparathyroidism type 1B (PHP1B) are imprinting disorders (ID) caused by deregulation of the imprinted gene clusters located at 11p15.5 and 20q13.32, respectively. In both of these diseases a subset of the patients is affected by multi-locus imprinting disturbances (MLID). In several families, MLID is associated with damaging variants of maternal-effect genes encoding protein components of the subcortical maternal complex (SCMC). However, frequency, penetrance and recurrence risks of these variants are still undefined. In this study, we screened two cohorts of BWS patients and one cohort of PHP1B patients for the presence of MLID, and analysed the positive cases for the presence of maternal variants in the SCMC genes by whole exome-sequencing and in silico functional studies.
RESULTS
We identified 10 new cases of MLID associated with the clinical features of either BWS or PHP1B, in which segregate 13 maternal putatively damaging missense variants of the SCMC genes. The affected genes also included KHDC3L that has not been associated with MLID to date. Moreover, we highlight the possible relevance of relatively common variants in the aetiology of MLID.
CONCLUSION
Our data further add to the list of the SCMC components and maternal variants that are involved in MLID, as well as of the associated clinical phenotypes. Also, we propose that in addition to rare variants, common variants may play a role in the aetiology of MLID and imprinting disorders by exerting an additive effect in combination with rarer putatively damaging variants. These findings provide useful information for the molecular diagnosis and recurrence risk evaluation of MLID-associated IDs in genetic counselling.
Topics: Beckwith-Wiedemann Syndrome; DNA Methylation; Genomic Imprinting; Humans; Proteins; Pseudohypoparathyroidism
PubMed: 35643636
DOI: 10.1186/s13148-022-01292-w -
Journal of Bone and Mineral Research :... May 2020Pseudohypoparathyroidism type 1A (PHP1A) and pseudopseudohypoparathyroidism (PPHP) are two rare autosomal dominant disorders caused by loss-of-function mutations in the...
Pseudohypoparathyroidism type 1A (PHP1A) and pseudopseudohypoparathyroidism (PPHP) are two rare autosomal dominant disorders caused by loss-of-function mutations in the imprinted Guanine Nucleotide Binding Protein, Alpha Stimulating Activity (GNAS) gene, coding G α. PHP1A is caused by mutations in the maternal allele and results in Albright's hereditary osteodystrophy (AHO) and hormonal resistance, mainly to the parathormone (PTH), whereas PPHP, with AHO features and no hormonal resistance, is linked to mutations in the paternal allele. This study sought to investigate parental transmission of GNAS mutations. We conducted a retrospective study in a population of 204 families with 361 patients harboring GNAS mutations. To prevent ascertainment bias toward a higher proportion of affected children due to the way in which data were collected, we excluded from transmission analysis all probands in the ascertained sibships. After bias correction, the distribution ratio of the mutated alleles was calculated from the observed genotypes of the offspring of nuclear families and was compared to the expected ratio of 50% according to Mendelian inheritance (one-sample Z-test). Sex ratio, phenotype of the transmitting parent, and transmission depending on the severity of the mutation were also analyzed. Transmission analysis was performed in 114 nuclear families and included 250 descendants. The fertility rates were similar between male and female patients. We showed an excess of transmission from mother to offspring of mutated alleles (59%, p = .022), which was greater when the mutations were severe (61.7%, p = .023). Similarly, an excess of transmission was found when the mother had a PHP1A phenotype (64.7%, p = .036). By contrast, a Mendelian distribution was observed when the mutations were paternally inherited. Higher numbers of females within the carriers, but not in noncarriers, were also observed. The mother-specific transmission ratio distortion (TRD) and the sex-ratio imbalance associated to PHP1A point to a role of G α in oocyte biology or embryogenesis, with implications for genetic counseling. © 2019 American Society for Bone and Mineral Research.
Topics: Child; Chromogranins; Female; GTP-Binding Protein alpha Subunits, Gs; Humans; Male; Maternal Inheritance; Mutation; Pseudohypoparathyroidism; Retrospective Studies
PubMed: 31886927
DOI: 10.1002/jbmr.3948 -
Mutation Research. Reviews in Mutation... 2024GNAS (guanine nucleotide-binding protein, alpha stimulating) is an imprinted gene that encodes Gα, the α subunit of the heterotrimeric stimulatory G protein. This... (Review)
Review
BACKGROUND
GNAS (guanine nucleotide-binding protein, alpha stimulating) is an imprinted gene that encodes Gα, the α subunit of the heterotrimeric stimulatory G protein. This subunit mediates the signalling of a diverse array of G protein-coupled receptors (GPCRs), including the melanocortin 4 receptor (MC4R) that serves a pivotal role in regulating food intake, energy homoeostasis, and body weight. Genetic or epigenetic alterations in GNAS are known to cause pseudohypoparathyroidism in its different subtypes and have been recently associated with isolated, early-onset, severe obesity. Given the diverse biological functions that Gα serves, multiple molecular mechanisms involving various GPCRs, such as MC4R, β- and β-adrenoceptors, and corticotropin-releasing hormone receptor, have been implicated in the pathophysiology of severe, early-onset obesity that results from genetic or epigenetic GNAS changes.
SCOPE OF REVIEW
This review examines the structure and function of GNAS and provides an overview of the disorders that are caused by defects in this gene and may feature early-onset obesity. Moreover, it elucidates the potential molecular mechanisms underlying Gα deficiency-induced early-onset obesity, highlighting some of their implications for the diagnosis, management, and treatment of this complex condition.
MAJOR CONCLUSIONS
Gα deficiency is an underappreciated cause of early-onset, severe obesity. Therefore, screening children with unexplained, severe obesity for GNAS defects is recommended, to enhance the molecular diagnosis and management of this condition.
Topics: Humans; GTP-Binding Protein alpha Subunits, Gs; Chromogranins; Epigenesis, Genetic; Obesity; Animals; Pseudohypoparathyroidism; Mutation; Receptor, Melanocortin, Type 4; Age of Onset
PubMed: 38103632
DOI: 10.1016/j.mrrev.2023.108487 -
Frontiers in Cell and Developmental... 2023Imprinting disorders are congenital diseases caused by dysregulation of genomic imprinting, affecting growth, neurocognitive development, metabolism and cancer...
Imprinting disorders are congenital diseases caused by dysregulation of genomic imprinting, affecting growth, neurocognitive development, metabolism and cancer predisposition. Overlapping clinical features are often observed among this group of diseases. In rare cases, two fully expressed imprinting disorders may coexist in the same patient. A dozen cases of this type have been reported so far. Most of them are represented by individuals affected by Beckwith-Wiedemann spectrum (BWSp) and Transient Neonatal Diabetes Mellitus (TNDM) or BWSp and Pseudo-hypoparathyroidism type 1B (PHP1B). All these patients displayed Multilocus imprinting disturbances (MLID). Here, we report the first case of co-occurrence of BWS and PHP1B in the same individual in absence of MLID. Genome-wide methylation and SNP-array analyses demonstrated loss of methylation of the :TSS-DMR on chromosome 11p15.5 as molecular cause of BWSp, and upd(20)pat as cause of PHP1B. The absence of MLID and the heterodisomy of chromosome 20 suggests that BWSp and PHP1B arose through distinct and independent mechanism in our patient. However, we cannot exclude that the rare combination of the epigenetic defect on chromosome 11 and the UPD on chromosome 20 may originate from a common so far undetermined predisposing molecular lesion. A better comprehension of the molecular mechanisms underlying the co-occurrence of two imprinting disorders will improve genetic counselling and estimate of familial recurrence risk of these rare cases. Furthermore, our study also supports the importance of multilocus molecular testing for revealing MLID as well as complex cases of imprinting disorders.
PubMed: 37635873
DOI: 10.3389/fcell.2023.1237629 -
The Journal of Clinical Endocrinology... Oct 2021Patients with pseudohypoparathyroidism type 1b (PHP1b) show disordered imprinting of the maternal GNAS allele or paternal uniparental disomy (UPD). Genetic deletions in...
CONTEXT
Patients with pseudohypoparathyroidism type 1b (PHP1b) show disordered imprinting of the maternal GNAS allele or paternal uniparental disomy (UPD). Genetic deletions in STX16 or in upstream exons of GNAS are present in many familial but not sporadic cases.
OBJECTIVE
Characterization of epigenetic and genetic defects in patients with PHP1b.
DESIGN AND PATIENTS
DNA from 84 subjects, including 26 subjects with sporadic PHP1b, 27 affected subjects and 17 unaffected and/or obligate gene carriers from 12 PHP1b families, 11 healthy individuals, and 3 subjects with PHP1a was subjected to quantitative pyrosequencing of GNAS differentially methylated regions (DMRs), microarray analysis, and microsatellite haplotype analysis.
SETTING
Academic medical center.
MAIN OUTCOME MEASUREMENTS
Molecular pathology of PHP1b.
RESULTS
Healthy subjects, unaffected family members and obligate carriers of paternal PHP1b alleles, and subjects with PHP1a showed normal methylation of all DMRs. All PHP1b subjects showed loss of methylation (LOM) at the exon A/B DMR. Affected members of 9 PHP1b kindreds showed LOM only at the exon A/B DMR, which was associated with a 3-kb deletion of STX16 exons 4 through 6 in 7 families and a novel deletion of STX16 and adjacent NEPEPL1 in 1 family. A novel NESP deletion was found in 1 of 2 other families with more extensive methylation defects. One sporadic PHP1b had UPD of 20q, 2 had 3-kb STX16 deletions, and 5 had apparent epigenetic mosaicism.
CONCLUSIONS
We found diverse patterns of defective methylation and identified novel or previously known mutations in 9 of 12 PHP1b families.
Topics: Adult; Child; Child, Preschool; DNA Methylation; Epigenesis, Genetic; Exons; Female; Follow-Up Studies; Gene Deletion; Heterozygote; High-Throughput Nucleotide Sequencing; Humans; Male; Pedigree; Prognosis; Pseudohypoparathyroidism; Uniparental Disomy
PubMed: 34157100
DOI: 10.1210/clinem/dgab460