Prevalence of Chiari malformation type 1 is increased in pseudohypoparathyroidism type 1A and associated with aberrant bone development.

BACKGROUND: Albright hereditary osteodystrophy (AHO) is caused by heterozygous inactivating mutations in GNAS. Patients with maternally-inherited mutations develop pseudohypoparathyroidism type 1A (PHP1A) with multi-hormone resistance and aberrant craniofacial and skeletal development among other abnormalities. Chiari malformation type 1 (CM1), a condition in which brain tissue extends into the spinal canal when the skull is too small, has been reported in isolated cases of PHP1A. It has been hypothesized to be associated with growth hormone (GH) deficiency. Given the adverse clinical sequelae that can occur if CM1 goes unrecognized, we investigated the previously undetermined prevalence of CM1, as well as any potential correlations with GH status, given the known increased prevalence of GH deficiency in PHP1A. We also investigated these metrics for low lying cerebellar tonsils (LLCT), defined as tonsillar descent less than 5 mm below the foramen magnum. In addition, we investigated possible correlations of CM1/LLCT with advanced hand/wrist bone ages and craniofacial abnormalities known to occur in PHP1A to determine whether premature chondrocyte differentiation and/or aberrant craniofacial development could be potential etiologies of CM1/LLCT through both human studies and investigations of our AHO mouse model. METHODS: We examined patients with PHP1A in our clinic and noticed CM1 more frequently than expected. Therefore, we set out to determine the true prevalence of CM1 and LLCT in a cohort of 54 mutation-confirmed PHP1A participants who had clinically-indicated brain imaging. We examined potential correlations with GH status, clinical features, biological sex, genotype, and hand/wrist bone age determinations. In addition, we investigated the craniofacial development in our mouse model of AHO (Gnas E1+/-m) by histologic analyses, dynamic histomorphometry, and micro-computerized tomographic imaging (MCT) in order to determine potential etiologies of CM1/LLCT in PHP1A. RESULTS: In our cohort of PHP1A, the prevalence of CM1 is 10.8%, which is at least 10-fold higher than in the general population. If LLCT is included, the prevalence increases to 21.7%. We found no correlation with GH status, biological sex, genotype, or hand/wrist bone age. Through investigations of our Gnas E1+/-m mice, the correlate to PHP1A, we identified a smaller cranial vault and increased cranial dome angle with evidence of hyperostosis due to increased osteogenesis. We also demonstrated that there was premature closure of the spheno-occipital synchondrosis (SOS), a cartilaginous structure essential to the development of the cranial base. These findings lead to craniofacial abnormalities and could contribute to CM1 and LLCT development in PHP1A. CONCLUSION: The prevalence of CM1 is at least 10-fold higher in PHP1A compared to the general population and 20-fold higher when including LLCT. This is independent of the GH deficiency that is found in approximately two-thirds of patients with PHP1A. In light of potential serious consequences of CM1, clinicians should have a low threshold for brain imaging. Investigations of our AHO mouse model revealed aberrant cranial formation including a smaller cranium, increased cranial dome angle, hyperostosis, and premature SOS closure rates, providing a potential etiology for the increased prevalence of CM1 and LLCT in PHP1A.

Prevalence of Pseudohypoparathyroidism and Nonsurgical Hypoparathyroidism in Japan in 2017: A Nationwide Survey.

BACKGROUND: Pseudohypoparathyroidism (PHP) and nonsurgical hypoparathyroidism (NS-HypoPT) are rare diseases with hypocalcemia, hyperphosphatemia, and high and low parathyroid hormone levels, respectively. In Japan, over 20 years have passed since the last survey on these diseases. We carried out a nationwide cross-sectional survey to estimate the prevalence of these diseases in 2018. METHODS: We conducted a nationwide mail-based survey targeting hospitals in 2018. From a total of 13,156 departments throughout Japan, including internal medicine, pediatrics, neurology, and psychiatry, 3,501 (27%) departments were selected using a stratified random sampling method. We asked each included department to report the number of patients with PHP and NS-HypoPT in 2017. RESULTS: The overall survey response rate was 52.0% (1,807 departments). The estimated number of patients with PHP and NS-HypoPT was 1,484 (95% confidence interval [CI], 1,143-1,825) and 2,304 (95% CI, 1,189-3,419), respectively; the prevalence per 100,000 population was 1.2 and 1.8, respectively. CONCLUSION: In this study, we generated estimates of the national prevalence of PHP and NS-HypoPT in Japan during 2017, which were found to be higher than those previously reported.

Clinical and Molecular Characteristics of GNAS Inactivation Disorders Observed in 18 Korean Patients.

BACKGROUND: The GNAS gene on chromosome 20q13.3 is a complex, imprinted locus regulated in a tissue-specific manner. GNAS inactivation disorders are a heterogeneous group of rare disorders caused by mutations and methylation defects. These are divided into pseudohypoparathyroidism (PHP) types 1A and 1B, pseudo-pseudohypoparathyroidism (PPHP), and progressive osseous heteroplasia (POH), depending on the presence or absence of hormone resistance, Albright's hereditary osteodystrophy (AHO), and ectopic ossification. METHODS: This study analyzed the clinical characteristics and molecular genetic backgrounds of 18 Korean patients from 16 families with a genetically confirmed GNAS defect. Auxological parameters, AHO phenotypes, types of hormonal resistance, family history, and molecular genetic disturbances were reviewed retrospectively. RESULTS: Nine (90%) patients with PHP1A showed resistance to parathyroid hormone (PTH) and all patients showed elevated thyroid-stimulating hormone (TSH) levels at diagnosis. Eight (80%) patients were managed with levothyroxine supplementation. Three of six patients with PHP1B had elevated TSH levels, but none of whom needed levothyroxine medication. AHO features were absent in PHP1B. Patients with PPHP and POH did not show any hormone resistance, and both of them were born as small for gestational age. Among the 11 families with PHP1A, PPHP, and POH, eight different (three novel) mutations in the GNAS gene were identified. Among the six patients with PHP1B, two were sporadic cases and four showed isolated loss of methylation at GNAS A/B:TSS-DMR. CONCLUSIONS: Clinical and molecular characteristics of Korean patients with GNAS inactivation disorders were described in this study. Also, we reaffirmed heterogeneity of PHP, contributing to further accumulation and expansion of current knowledge of this complex disease.

Inactivating PTH/PTHrP signaling disorders (iPPSDs): evaluation of the new classification in a multicenter large series of 544 molecularly characterized patients.

OBJECTIVE: Pseudohypoparathyroidism and related disorders belong to a group of heterogeneous rare diseases that share an impaired signaling downstream of Gsα-protein-coupled receptors. Affected patients may present with various combination of symptoms including resistance to PTH and/or to other hormones, ectopic ossifications, brachydactyly type E, early onset obesity, short stature and cognitive difficulties. Several years ago we proposed a novel nomenclature under the term of inactivating PTH/PTHrP signaling disorders (iPPSD). It is now of utmost importance to validate these criteria and/or improve the basis of this new classification. DESIGN: Retrospective study of a large international series of 459 probands and 85 relatives molecularly characterized. METHODS: Information on major and minor criteria associated with iPPSD and genetic results were retrieved from patient files. We compared the presence of each criteria according to the iPPSD subtype, age and gender of the patients. RESULTS: More than 98% of the probands met the proposed criteria for iPPSD classification. Noteworthy, most patients (85%) presented a combination of symptoms rather than a single sign suggestive of iPPSD and the overlap among the different genetic forms of iPPSD was confirmed. The clinical and molecular characterization of relatives identified familial history as an additional important criterion predictive of the disease. CONCLUSIONS: The phenotypic analysis of this large cohort confirmed the utility of the major and minor criteria and their combination to diagnose iPPSD. This report shows the importance of having simple and easily recognizable signs to diagnose with confidence these rare disorders and supports a better management of patients.

¿Se puede diagnosticar una enfermedad genética en base a caracteres fenotípicos? A propósito de un caso de pseudohipoparatiroidismo en Ecuador / Can a genetic condition be diagnosed based on phenotypic characteristics? A case of pseudohypoparathyroidism in Ecuador

El pseudohipoparatiroidismo (PHP) es un grupo heterogéneo de trastornos que tienen en común la resistencia a la hormona paratiroidea (PTH). A nivel mundial, se estima que la prevalencia es 0,79/100.0001, aunque depende del tipo de PHP analizado, y oscila entre 6,7 a 3,3 casos por millón de habitantes en Italia2 y Japón3, respectivamente. Entre 2000 y 2019 en la literatura mundial se han descrito aproximadamente 325 casos4, la mayoría de ellos en los países desarrollados, en los cuales, además, han sido documentados con estudios genéticos los subtipos de PHP. El subtipo 1a es el más común y representa el 70% de los casos1. En América Latina se han reportado 47 casos entre 2000 y 20205-10, siendo el subtipo más frecuentemente descrito el 1b, seguido del 1a ó 1c. En algunos casos por no disponer del estudio genético no es posible determinar con precisión a qué subtipo corresponden10. Describimos a continuación el caso clínico de un varón de 18 años con aspecto fenotípico de osteodistrofia hereditaria de Albright (AHO). (AU)

Pseudohypoparathyroidism is a rare disease of the endocrine gland. Its diagnosis should not be dismissed when hypocalcemia is accompanied by hyperphosphatemia and high levels of parathyroid hormone even if kidney failure and vitamin D deficiency do not occur. Although genetic studies provide a definitive diagnosis, biochemical tests that show hormonal resistance and phenotypic characteristics allow us to establish a diagnosis. Literature is limited in Latin America and few cases have been described. Here we report an 18-year-old male suffering pseudohypoparathyroidism and we discuss clinical characteristics, biochemical and radiographic findings, as well as treatment. (AU)

Dental anomalies and orthodontic characteristics in patients with pseudohypoparathyroidism.

BACKGROUND: Pseudohypoparathyroidism (PHP) is a rare and inherited disease caused by mutations in the GNAS-gene or upstream of the GNAS complex locus. It is characterized by end-organ resistance to PTH, resulting in hypocalcemia and hyperphosphatemia. We aimed to investigate the dental anomalies according to tooth types and the orthodontic characteristics of patients with PHP. METHODS: Using a cross-sectional design, 29 patients (23 females) with PHP, living in Denmark, were included, and their clinical intraoral photos and radiographs were examined. RESULTS: Pulp calcification was found in 76% of the patients. Blunting of root apex was present in 55% and shortening of root in 48% of the examined patients. Blunting and shortening of roots were seen more often in premolars than in other tooth types (pboth < 0.01). Crowding of lower anterior teeth was frequently observed (36%) as well as diastema in the upper arch (25%), midline diastema (18%), and Class III malocclusion (11%). CONCLUSION: In the present study population, the teeth were frequently affected by pulp calcification and/or deviation of the root morphology. Blunting and shortening of root(s) were more often seen in premolars than in other tooth types. Class III malocclusion was relatively prevalent. It is important to pay attention to dental anomalies and occlusion in order to provide adequate care for patients with PHP.

Cognitive and behavioral phenotype of children with pseudohypoparathyroidism type 1A.

Pseudohypoparathyroidism 1A (PHP1A) is a rare, genetic disorder. Most patients with PHP1A have cognitive impairment but this has not been systematically studied. We hypothesized that children with PHP1A would have lower intelligent quotient (IQ) scores than controls. To evaluate cognition and behavior, we prospectively enrolled children with PHP1A, one unaffected sibling (when available) and controls matched on BMI/age/gender/race. Evaluations included cognitive and executive function testing. Parents completed questionnaires on behavior and executive function. We enrolled 16 patients with PHP1A, 8 unaffected siblings, and 15 controls. Results are presented as mean (SD). The PHP1A group had a composite IQ of 85.9 (17.2); 25% had a composite IQ < -2 SD. The PHP1A group had significantly lower IQs than matched controls (composite IQ -17.3, 95%CI -28.1 to -6.5, p < 0.01) and unaffected siblings (composite IQ -21.5, 95%CI -33.9 to -9.1, p < 0.01). Special education services were utilized for 93% of the patients with PHP1A. Deficits were observed in executive function and parents reported delayed adaptive behavior skills and increased rates of attention deficit hyperactivity disorder. In conclusion, children with PHP1A have lower intelligence quotient scores, poorer executive function, delayed adaptive behavior skills, and increased behavior problems.

The Prevalence of GNAS Deficiency-Related Diseases in a Large Cohort of Patients Characterized by the EuroPHP Network.

CONTEXT: The term pseudohypoparathyroidism (PHP) was coined to describe the clinical condition resulting from end-organ resistance to parathormone (rPTH), caused by genetic and/or epigenetic alterations within or upstream of GNAS. Although knowledge about PHP is growing, there are few data on the prevalence of underlying molecular defects. OBJECTIVE: The purpose of our study was to ascertain the relative prevalence of PHP-associated molecular defects. DESIGN: With a specially designed questionnaire, we collected data from all patients (n = 407) clinically and molecularly characterized to date by expert referral centers in France, Italy, and Spain. RESULTS: Isolated rPTH (126/407, 31%) was caused only by epigenetic defects, 70% of patients showing loss of imprinting affecting all four GNAS differentially methylated regions and 30% loss of methylation restricted to the GNAS A/B:TSS-DMR. Multihormone resistance with no Albright's hereditary osteodystrophy (AHO) signs (61/407, 15%) was essentially due to epigenetic defects, although 10% of patients had point mutations. In patients with rPTH and AHO (40/407, 10%), the rate of point mutations was higher (28%) and methylation defects lower (about 70%). In patients with multihormone resistance and AHO (155/407, 38%), all types of molecular defects appeared with different frequencies. Finally, isolated AHO (18/407, 4%) and progressive osseous heteroplasia (7/407, 2%) were exclusively caused by point mutations. CONCLUSION: With European data, we have established the prevalence of various genetic and epigenetic lesions in PHP-affected patients. Using these findings, we will develop objective criteria to guide cost-effective strategies for genetic testing and explore the implications for management and prognosis.

Pseudohypoparathyroidism - epidemiology, mortality and risk of complications.

OBJECTIVE: Pseudohypoparathyroidism (PHP) is caused by a mutation within the GNAS gene or upstream of the GNAS complex locus. It is characterized by target organ resistance to PTH, resulting in hypocalcaemia and hyperphosphataemia. Studies in patients with PHP are limited. We sought to identify all patients in Denmark with PHP and access their mortality data and risk of complications. DESIGN: Patients were identified through the Danish National Patient Registry and a prescription database, with subsequent validation by investigation of patient charts. METHODS: For each case, three age- (±2 years) and gender-matched controls were randomly selected from the general background population. We identified a total of 60 cases, equal to a prevalence of 1·1/100 000 inhabitants. The average age at diagnosis was 13 years (range 1-62 years), and 42 were women. Only 14 patients had an identified mutation in the GNAS1 gene. RESULTS: Compared with controls, patients with PHP had an increased risk of neuropsychiatric disorders (P < 0·01), infections (P < 0·01), seizures (P < 0·01) and cataract (P < 0·01), whereas their risk of renal, cardiovascular, malignant disorders and fractures was compatible with the general background population. The same tendencies were found in a subgroup analysis in cases with genetically verified PHP. CONCLUSION: Patients with PHP have an increased risk of neuropsychiatric disorders, infections, cataract and seizures, whereas mortality among PHP patients is compatible with that in the background population.

Increased Prevalence of Sleep Apnea in Children with Pseudohypoparathyroidism Type 1a.

BACKGROUND/AIMS: Pseudohypoparathyroidism type 1a (PHP1a) is a rare genetic disorder. This study aimed to determine the prevalence of sleep apnea in children with PHP1a. METHODS: Nineteen patients with PHP1a between the age of 2 and 21 years were enrolled prospectively using online advertisements. Parents completed a medical history and surveys to assess sleep behavior. Polysomnography records were obtained when available. In addition, 18 subjects were identified in a retrospective chart review of de-identified medical records with 2.3 million patient charts. RESULTS: Parents reported sleep disturbance (94%) and daytime somnolence (81%) in their children with PHP1a. In the retrospective chart review, 39% had a history of sleep apnea versus 8.8% of a similarly obese control group. In the combined analysis (n = 31), 52% had a history of snoring and 45% had a diagnosis of sleep apnea. Patients were obese with a mean BMI z-score of 2.20 ± 0.59. Patients with sleep apnea were significantly younger than those without a diagnosis (8.1 ± 5.4 vs. 12.8 ± 5.0 years, p = 0.02). CONCLUSIONS: Children with PHP1a have a 4.4-fold greater relative risk of sleep apnea than similarly obese children. Screening for sleep apnea in this population may be warranted to prevent adverse health outcomes.

Pseudohypoparathyroidism with Hashimoto's thyroiditis and Turner syndrome: a case report.

OBJECTIVE: To report the case of an individual with PHP, Turner syndrome and Hashimoto's thyroiditis. CASE: A 16-year-old girl was referred to our hospital with chief complaint of short stature. She presented with round chubby facies, short neck, obesity and short stature. Radiography indicated short metatarsals and metacarpals, which mainly affected the second, third and fourth digits. Biochemistry revealed hyperphosphatemia, increased serum concentrations of parathyroid hormone and thyroid stimulating hormone, elevated levels of follicular-stimulating hormone and prolactin, and increased thyroid peroxidase antibody and thyroglobulin antibody. Radiographic examination revealed delayed bone age and pelvic ultrasonography demonstrated an immature uterus. Karyotype analysis showed 46,X,i(Xq10), while molecular analysis revealed a same sense mutation in exon 5 of GNAS (ATC → ATT, Ile).The specific diagnosis was made of Turner syndrome in the presence of Hashimoto's thyroiditis and PHP. She was treated with calcium supplementation, calcitriol and thyroxine. CONCLUSIONS: This is the first case report to describe a combination of Turner syndrome with these other clinical entities, and their co-existence should be considered and further investigated.

Energy expenditure in obese children with pseudohypoparathyroidism type 1a.

CONTEXT: Patients with pseudohypoparathyroidism type 1a (PHP-1a) develop early-onset obesity. The abnormality in energy expenditure and/or energy intake responsible for this weight gain is unknown. OBJECTIVE: The aim of this study was to evaluate energy expenditure in children with PHP-1a compared with obese controls. PATIENTS: We studied 6 obese females with PHP-1a and 17 obese female controls. Patients were recruited from a single academic center. MEASUREMENTS: Resting energy expenditure (REE) and thermogenic effect of a high fat meal were measured using whole room indirect calorimetry. Body composition was assessed using whole body dual energy x-ray absorptiometry. Fasting glucose, insulin, and hemoglobin A1C were measured. RESULTS: Children with PHP-1a had decreased REE compared with obese controls (P<0.01). After adjustment for fat-free mass, the PHP-1a group's REE was 346.4 kcals day(-1) less than obese controls (95% CI (-585.5--106.9), P<0.01). The thermogenic effect of food (TEF), expressed as percent increase in postprandial energy expenditure over REE, was lower in PHP-1a patients than obese controls, but did not reach statistical significance (absolute reduction of 5.9%, 95% CI (-12.2-0.3%), P=0.06). CONCLUSIONS: Our data indicate that children with PHP-1a have decreased REE compared with the obese controls, and that may contribute to the development of obesity in these children. These patients may also have abnormal diet-induced thermogenesis in response to a high-fat meal. Understanding the causes of obesity in PHP-1a may allow for targeted nutritional or pharmacologic treatments in the future.

HTLV-1-associated myelopathy/tropical spastic paraparesis with pseudohypoparathyroidism.

In many short-stature patients with human T-lymphotrophic virus type I-associated myelopathy/tropical spastic paraparesis (HAM/TSP), signs and symptoms were manifested during childhood. Successive investigations revealed 12 of 14 short-stature patients with pseudohypoparathyroidism (PHP) from the findings of short metacarpi, parathyroid hormone infusion test, immunoblotting of erythrocyte membrane, or lymphocytic Northern blotting of Gsalpha. Patients with PHP probably showed HAM/TSP based on their modified immunologic status. Human T-lymphotrophic virus type I infection did not induce PHP, but PHP may be a risk factor for the occurrence of HAM/TSP.

[Pseudohypoparathyroidism]. / Rzekoma niedoczynnosc przytarczyc.

The article presents data concerning pseudohypoparathyroidism (PH TP). It is an unusual disease, which is characterized by the resistance of bones and kidney to PTH, followed by hypocalcaemia, hyperphospha-taemia, glandulary hypertrophy and hypersecretion of PTH. Patients with PTHT clinically manifest tetany seizures, soft tissue calcifications and many congenital malformations. The disease has a genetic etiology, it is connected with chromosome X and more often found in women. Clinical symptoms may be different and depend on genetic defect or its selectivity with reference to the tissues. At present we can distinguish three types of PHPT and pseudo-pseudo-HPT. The disease usually appears in the infancy. Early diagnosis and vitamin D3 or calcium treatment seem to be the most important for patient's condition. Too late treatment threatens with brain calcification followed by neurological defects and mental retardation. The long-lasting effect of PTH in bones can lead to their destruction, if bone receptors are completely sensitive.

Prevalence of idiopathic hypoparathyroidism and pseudohypoparathyroidism in Japan.

A nationwide epidemiologic survey of idiopathic hypoparathyroidism and pseudohypoparathyroidism was conducted in 1998 to clarify the prevalence of the two disorders in Japan. From a total of 14,100 departments of pediatrics, internal medicine, neurology, and endocrinology in whole Japan, 2952 (20.9%) study departments were selected at random. Of these departments receiving the first questionnaire, 1855 (62.8%) responded. From these departments 390 patients with idiopathic hypoparathyroidism and 203 with pseudohypoparathyroidism who visited the hospitals in 1997 were reported. The total numbers of patients were estimated to be 900 (690-1100) for idiopathic hypoparathyroidism and 430 (330-520) for pseudohypoparathyroidism (95% confidence intervals in parentheses). Using these data, the period prevalence of the diseases were 7.2 (5.5-8.8) per million population in idiopathic hypoparathyroidism, and 3.4 (2.6-4.2) in pseudohypoparathyroidism (95% confidence intervals in parentheses).

Pseudohypoparathyroidism-associated spinal stenosis.

STUDY DESIGN: Pseudohypoparathyroidism associated with disorders of the spine is rarely reported. In this report, the authors present a case of pseudohypoparathyroidism in a 41-year-old man who had narrow spinal canal and multiple disc herniation in the cervical spine. SUMMARY OF BACKGROUND DATA: The patient had progressive spastic tetraplegia due to cervical cord compression caused by multiple disc herniations at the C3-C4, C4-5, and C5-C6 levels in the developmentally narrow spinal canal. Based on the features of Albright's osteodystrophy, serum laboratory results, and an Ellsworth-Howard test, the diagnosis of pseudohypoparathyroidism, type I was confirmed. METHODS: The patient underwent expansive laminoplasty at C3 through C6 levels. RESULTS: His symptoms have gradually improved during the 1-year and 6-month periods after the surgery. CONCLUSIONS: A case of pseudohypoparathyroidism-associated spinal stenosis was reported.

["Hormone receptor diseases" in Japan: A nation-wide survey for testicular feminization syndrome, pseudohypoparathyroidism, nephrogenic diabetes insipidus, Bartter's syndrome and congenital adrenocortical unresponsiveness to ACTH (author's transl)].

A nation-wide survey for five "hormone receptor diseases" was carried out. For the first survey, an inquiry was sent to all hospitals in Japan having more than 200 beds, in order to determine how many patients there were between 1968-1977. A further detailed survey was carried out on patients who were reported in the first survey. The approximate numbers of patients in Japan estimated from these surveys are the following: testicular feminization syndrome (TFS), 390; pseudohypoparathyroidism (PHP), 220, nephrogenic diabetes insipidus (NDI), 280; Bartter's syndrome, 90; congenital adrenocortical unresponsiveness to ACTH (CAUA), 18. In 73 cases of TFS, partial virilization was observed in 23% (the incomplete form). Testes were found in all cases and the epididymis in 84%, whereas none of the patients had seminal vesicles. PHP consisted of 38 Type-I cases, 6 Type-II cases and 25 unclassified cases. There were 27 males and 42 females. Skeletal anomalies were found in two-thirds of the patients. Grades of hypocalcemia and soft tissue calcification were more prominent in Type I. After treatment, none of the Type-I patients showed normal urinary cyclic AMP response to parathormone, although urinary phosphate response was normalized in one and markedly improved in 4. In 78 patients with NDI, there were 67 males and 11 females. The age of the onset of NDI ranged from 0 to over 50, but 22 out of 29 cases of hereditary NDI had the onset at age 0. There seemed to be at least two subtypes; one beginning in the neonatal period or early childhood, and the other having the onset in late childhood or adult. The important initial symptoms were fever and anorexia in the early onset type. Growth retardation was remarkable in early childhood. Diuretics were effective in most of the cases. There were 22 male and 12 female patients with Bartter's syndrome. Indomethacin was effective in 9 out of 10 patients studied.