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Pseudohypoparathyroidism (PHP) comprises a cluster of heterogeneous diseases characterized by hypocalcemia and hyperphosphatemia due to parathyroid hormone (PTH) resistance. PHP type 1B (PHP1B) is caused by heterozygous maternal deletions within GNAS or STX16. STX16 exon 2–6 deletion is commonly observed in autosomal dominant (AD)-PHP1B, while sporadic PHP1B commonly results from methylation abnormalities of maternal differentially methylated regions and remains unclear at the molecular level. A 39-year-old male patient with PHP1B, who had his first seizure at 15 years of age, presented to our hospital. The methylation-specific multiplex ligation-dependent probe amplification results showed a half-reduced copy number of STX16 exon 5–7 and loss of methylation at GNAS exon A/B. His mother also had a half-reduced copy number of STX16 exon 5–7 but with normal methylation of GNAS. His father has a normal copy number of STX16 and normal methylation of GNAS. For the recognition and early diagnosis of this kind of disease, here we report the clinical symptoms, auxiliary examinations, genetic testing characteristics, and treatment of the patient. [ABSTRACT FROM AUTHOR]

Abstract Background Pseudohypoparathyroidism (PHP) is caused by loss-of-function mutations at the GNAS gene (as in the PHP type 1A; PHP1A), de novo or inherited at heterozygous state, or by epigenetic alterations at the GNAS locus (as in the PHP1B). The condition of PHP refers to a heterogeneous group of disorders that share common clinical and biological features of PTH resistance. Manifestations related to resistance to other hormones are also reported in many patients with PHP, in association with the phenotypic picture of Albright hereditary osteodystrophy characterized by short stature, round facies, subcutaneous ossifications, brachydactyly, mental retardation and, in some subtypes, obesity. The purpose of our study is to report a new mutation in the GNAS gene and to describe the significant phenotypic variability of three sisters with PHP1A bearing the same mutation. Case presentation We describe the cases of three sisters with PHP1A bearing the same mutation but characterized by a significantly different phenotypic picture at onset and during follow-up in terms of clinical features, auxological pattern and biochemical changes. Clinical exome sequencing revealed a never before described heterozygote mutation in the GNAS gene (NM_000516.5 c.118_139 + 51del) of autosomal dominant maternal transmission in the three siblings, confirming the diagnosis of PHP1A. Conclusions This study reported on a novel mutation of GNAS gene and highlighted the clinical heterogeneity of PHP1A characterized by wide genotype–phenotype variability. The appropriate diagnosis has crucial implications for patient care and long-term multidisciplinary follow-up.

Pseudohypoparathyroidism (PHP) type 1a (PHP 1a) is a rare hereditary disorder characterized by target organ resistance to hormonal signaling and the Albright hereditary osteodystrophy (AHO) phenotype, which features round facial features, short fingers, subcutaneous calcifications, short stature, obesity, and intellectual disability. Progressive osseous heteroplasia (POH) is another rare disorder characterized by heterotopic ossification (HO) that progressively affects skin, subcutaneous tissues, and deep skeletal muscle. PHP 1a is inherited maternally due to a GNAS mutation, while pure POH is inherited paternally. This case study presented a Chinese boy with congenital hypothyroidism, tonic-clonic seizures, hypoparathyroidism, AHO, POH, and joint fixation deformity. Sequencing analysis of GNAS-Gsα revealed a heterozygous C.432+2T>C(P.?) variant (NM_000516.7) affecting the canonical splice donor site of intron 5 in the boy and his mother, indicating maternal inheritance of a GNAS mutation. The patient was diagnosed with POH overlap syndrome (POH/PHP 1a). Following calcium and calcitriol supplementation, he experienced a reduction in seizures, and surgery was performed to correct the joint fixation deformity caused by HO. This case report provided valuable insights into the genotype-phenotype correlations of POH overlap syndrome and underscored the significance of genetic testing in diagnosing rare diseases.

Abstract Background Albright’s hereditary osteodystrophy (AHO) is an inherited disorder which is caused by an inactivating variant in the GNAS gene. AHO appears associated to either pseudohypoparathyroidism 1a (PHP1a) when GNAS gene is maternally inherited or to pseudo-pseudohypoparathyroidism (PPHP) when it is paternally inherited. We describe the clinical and biochemical characteristics of two patients, a boy and his mother with a novel heterozygous missense variant of GNAS gene. Case presentation The boy presented with typical AHO phenotype (early-onset obesity, round face, short neck, shortened fifth metacarpal bone, developmental retardation, but without short stature and subcutaneous calcifications), multiple hormone resistance including PTH, TSH and ACTH, and mild calcification in the right basal ganglia. The mother only presented with brachydactyly and short stature, without hormone resistance and other signs of AHO. Whole-exome sequencing identified in the son and his mother a novel heterozygous missense variant (p. Val375Leu) in exon 13 of GNAS gene. The diagnosis of PHP-1a for the son and PPHP for the mother were confirmed. Conclusion This study further expands the spectrum of known GNAS pathogenic variants, and also demonstrates the heterogeneous phenotype of AHO due to a novel GNAS pathogenic variant.

A teenage Afghan girl presented with seizure. Clinical features and laboratory investigations revealed elevated serum parathormone, high phosphate levels with low serum calcium. In third‐world countries, diagnosis of rare disorders, such as Albright hereditary osteodystrophy (AHO), can usually be delayed due to scarcity of standard medical and diagnostic services. [ABSTRACT FROM AUTHOR]

Abstract A teenage Afghan girl presented with seizure. Clinical features and laboratory investigations revealed elevated serum parathormone, high phosphate levels with low serum calcium. In third‐world countries, diagnosis of rare disorders, such as Albright hereditary osteodystrophy (AHO), can usually be delayed due to scarcity of standard medical and diagnostic services.

PTH resistance is characterized by hypocalcemia and hyperphosphatemia in the presence of elevated PTH concentrations, resulting in pseudohypoparathyroidism, which is subdivided into different types according to its different pathogenesis and phenotype. PTH receptor is the alpha subunit of stimulatory G protein (Gsα)-coupled receptor. Pathogenic variants of GNAS gene, encoding for Gsα, lead to reduced Gsα function and PTH resistance. We report a patient with PHP type 1a, with no documented evidence of hypocalcemia, presenting with AHO phenotype and multihormone resistance to PTH, TSH, and GnRH. Her genetic testing showed a novel heterozygous pathogenic variants, a c.934T > G change in exon 11 in adenylate cyclase stimulatory G protein that has not been reported in the literature so far. [ABSTRACT FROM AUTHOR]

Background: Albright's hereditary osteodystrophy (AHO) is an inherited disorder which is caused by an inactivating variant in the GNAS gene. AHO appears associated to either pseudohypoparathyroidism 1a (PHP1a) when GNAS gene is maternally inherited or to pseudo-pseudohypoparathyroidism (PPHP) when it is paternally inherited. We describe the clinical and biochemical characteristics of two patients, a boy and his mother with a novel heterozygous missense variant of GNAS gene. Case presentation: The boy presented with typical AHO phenotype (early-onset obesity, round face, short neck, shortened fifth metacarpal bone, developmental retardation, but without short stature and subcutaneous calcifications), multiple hormone resistance including PTH, TSH and ACTH, and mild calcification in the right basal ganglia. The mother only presented with brachydactyly and short stature, without hormone resistance and other signs of AHO. Whole-exome sequencing identified in the son and his mother a novel heterozygous missense variant (p. Val375Leu) in exon 13 of GNAS gene. The diagnosis of PHP-1a for the son and PPHP for the mother were confirmed. Conclusion: This study further expands the spectrum of known GNAS pathogenic variants, and also demonstrates the heterogeneous phenotype of AHO due to a novel GNAS pathogenic variant. [ABSTRACT FROM AUTHOR]

PTH resistance is characterized by elevated parathyroid hormone (PTH) levels, hypocalcemia, hyperphosphatemia and it is classically associated with GNAS locus genetic or epigenetic defects. Inactivating PTH/PTHrP signaling disorders (iPPSD) define overlapping phenotypes based on their molecular etiology. iPPSD1 is associated with PTH1R variants and variable phenotypes including ossification anomalies and primary failure of tooth eruption but no endocrine disorder. Here we report on a 10-month-old child born from consanguineous parents, who presented with mild neurodevelopmental delay, seizures, enlarged fontanelles, round face, and bilateral clinodactyly. Hand x-rays showed diffuse delayed bone age, osteopenia, short metacarpal bones and cone-shaped distal phalanges. A diagnosis of PTH resistance was made on the basis of severe hypocalcemia, hyperphosphatemia, elevated PTH and normal vitamin D levels on blood sample. The patient was treated with calcium carbonate and alfacalcidol leading to rapid bio-clinical improvement. Follow-up revealed multiple agenesis of primary teeth and delayed teeth eruption, as well as Arnold-Chiari type 1 malformation requiring a ventriculoperitoneal shunt placement. GNAS gene analysis showed no pathogenic variation, but a likely pathogenic homozygous substitution c.723C>G p.(Asp241Glu) in PTH1R gene was found by trio-based whole exome sequencing. We studied the deleterious impact of the variant on the protein conformation with bioinformatics tools. In conclusion, our study reports for the first time PTH resistance in a child with a biallelic PTH1R mutation, extending thereby the clinical spectrum of iPPSD1 phenotypes. [ABSTRACT FROM AUTHOR]

Osteoma cutis is a condition characterized by theformation of bone within the skin. Such aberrantossification of the skin and subcutaneous tissue isconsidered primary when it arises in the absence ofunderlying tissue damage or a preceding cutaneouslesion. Conversely, secondary osteoma cutis occurswhen skin ossification is the result of a pre-existingskin lesion, trauma, or inflammatory process [1,2].Although rare, primary osteoma cutis has beenassociated with a number of different geneticdisorders. Albright hereditary osteodystrophy (AHO),a condition first described in 1942 by Fuller Albright,is an autosomal dominant metabolic disorder causedby a mutation in the GNAS1 gene [3]. This disease isassociated with a variety of phenotypic traits includingcutaneous ossification, short stature, brachydactyly,obesity, and mental retardation. It should be notedthat brachydactyly is the most specific feature of AHO[4]. However, owing to variable expressivity individualsmay present only with a subset of these symptoms [5,6]. The cutaneous ossification observed in patientswith AHO may be seen in infancy or early childhoodand is sometimes the earliest presenting symptom.Nonetheless, because clinical features of AHO canbe seen in the absence of metabolic derangements(i.e. normal serum calcium, phosphorus, and PTHlevels) an early diagnosis is often missed and delayedfor many years. Herein, we present a case of miliaryosteoma cutis of the face in a 68 year-old woman withphenotypic features of AHO and laboratory studiesconsistent with type 1a PHP.

Osteoma cutis is the presence of bone within the dermis or subcutaneous tissue. This condition may occur sporadically or secondary to other dermatologic or genetic conditions. We present a 12-year-old girl with pseudohypoparathyroidism type-Ia who developed osteoma cutis on the right thigh.

Pseudohypoparathyroidism (PHP) is a rare hormone resistance syndrome caused by mutations in GNAS. 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, P  = 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, P  = 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, P  = 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. [ABSTRACT FROM AUTHOR]

Pseudohypoparathyroidism (PHP) is a heterogeneous group of disorder with parathormone target organ resistance, characterized by hypocalcemia, hyperphosphatemia and high blood parathormone (PTH). Typical phenotypic symptoms and additional hormonal resistance can be observed in type Ia, which is also known as Albright hereditary osteodystrophy. Our patient was an eight-year and nine-month old girl with typical Albright’s hereditary osteodystrophy phenotype including short stature, obesity, round face, low nasal bridge, shortened metacarpals, and mild mental retardation. In her biochemical examination, high PTH level and hypothyroidism is detected in spite of normal calcium and phosphor levels. As a result of clinic and laboratory tests, the findings were consistent with PHP type Ia with normocalcemia. In her guanine nucleotide binding protein (G protein), alpha stimulating activity polypeptide 1 (GNAS 1) gene serial analysis, C-308T>C (p1103T) transformation was detected, which was previously reported in a PHP type Ia patient. In this report, we’ve aimed to emphasize the fact that calcium and phosphor level in the blood of the patient with PHP type Ia can be measured normal.

Abstract Background Pseudohypoparathyroidism type 1B (PHP1B; MIM#603233) is a rare imprinting disorder (ID), associated with the GNAS locus, characterized by parathyroid hormone (PTH) resistance in the absence of other endocrine or physical abnormalities. Sporadic PHP1B cases, with no known underlying primary genetic lesions, could represent true stochastic errors in early embryonic maintenance of methylation. Previous data confirmed the existence of different degrees of methylation defects associated with PHP1B and suggested the presence of mosaicism, a phenomenon already described in the context of other IDs. Results With respect to mosaic conditions, the study of multiple tissues is a necessary approach; thus, we investigated somatic cell lines (peripheral blood and buccal epithelium and cells from the urine sediment) descending from different germ layers from 19 PHP patients (11 spor-PHP1B, 4 GNAS mutated PHP1A, and 4 PHP with no GNAS (epi)genetic defects) and 5 healthy controls. We identified 11 patients with epigenetic defects, further subdivided in groups with complete or partial methylation defects. The recurrence of specific patterns of partial methylation defects limited to specific CpGs was confirmed by checking methylation profiles of spor-PHP1B patients diagnosed in our lab (n = 56). Underlying primary genetic defects, such as uniparental disomy or deletion, potentially causative for the detected partial methylation were excluded in all samples. Conclusions Our data showed no differences of methylation levels between organs and tissues from the same patient, so we concluded that the epimutation occurred in early post-zygotic phases and that the partial defects were mosaics. The number of patients with no detectable (epi)genetic GNAS defects was too small to exclude epimutations occurring in later post-zygotic phases, affecting only selected tissues different from blood, thus leading to underdiagnosis during routine molecular diagnosis. Finally, we found no correlation between methylation ratios, representing the proportion of epimutated cells, and the clinical presentation, further confirming the hypothesis of a threshold effect of the GNAS loss of imprinting leading to an “all-or-none” phenotype.

Pseudohypoparathyroidism (PHP) is a rare endocrine disorder derived from the defective activation of the cAMP pathway by the parathyroid hormone secondary to GNAS molecular defects. PHP subtypes are defined by the presence/absence of specific clinical/biochemical features. PHP1A is characterized by resistance to multiple hormones with features of Albright hereditary osteodystrophy (AHO), while pseudopseudohypoparathyroidism (PPHP) is characterized by AHO in the absence of PTH resistance. Small subsets of PHP and PPHP patients without known molecular defects have been re-diagnosed as being affected by the brachydactyly-mental retardation syndrome (BDMR), also known as the AHO-like syndrome. This study aimed to analyse 24 PHP1A and 51 PPHP patients without a molecular diagnosis for the presence of BDMR-associated 2q37 deletions to improve the differential diagnosis and to identify features that might help to avoid a misdiagnosis. Molecular investigations identified 4 deletions in 4 unrelated patients. The affected patients showed a combination of the most pathognomonic AHO features. Of note, 3 of the patients also displayed mild PTH resistance, and none of the patients developed ectopic ossifications. Our work confirmed the rarity of the misdiagnosis of BDMR in PHP patients through the identification of 4 patients bearing a 2q37 deletion in a cohort of 73 PHP patients (5.3%). Three patients with the deletion presented a PHP1A phenotype in the absence of any BDMR-specific findings. Further studies on larger case series are needed to elucidate the overlap between these clinical entities and to allow the early identification of patients.

Resumen: Desde que en 1942 Albright y colaboradores describieran por primera vez el pseudohipoparatiroidismo como la existencia de hipocalcemia e hiperfosfatemia asociadas a resistencia tisular a la hormona paratiroidea (PTH) en presencia de una función renal normal, se han realizado grandes avances en la caracterización clínica y genética de los pacientes afectos de esta enfermedad. De hecho, no solo se han identificado las alteraciones moleculares responsables, sino que se ha podido establecer que variantes en otros genes de la misma vía de señalización, PTH/PTHrP a través de la proteína Gsα, son la causa de enfermedades que comparten determinadas manifestaciones clínicas con el pseudohipoparatiroidismo.En el ámbito pediátrico, los primeros síntomas o signos que deben hacernos pensar en alteraciones en esta vía son la presencia de osificaciones subcutáneas, la braquidactilia y/o la obesidad de inicio precoz, seguidas en el tiempo por la posible aparición de resistencia a la PTH. Esta sospecha clínica deberá ser confirmada mediante un diagnóstico molecular que permita el correcto seguimiento clínico coordinado y multidisciplinar. Entre los aspectos a tener en cuenta en la atención de estos pacientes se incluye la evaluación al diagnóstico y seguimiento de la eventual presencia de resistencia a la PTH y a la hormona tirotropa (TSH), deficiencia de hormona de crecimiento (GH), hipogonadismo, alteraciones esqueléticas, alteraciones de la salud dental, obesidad, resistencia a la acción de la insulina, intolerancia a la glucosa o diabetes mellitus tipo 2 e hipertensión, así como osificaciones ectópicas (subcutáneas o con afectación de tejidos más profundos) y alteración del desarrollo neurocognitivo. Abstract: Since Albright and co-workers described pseudohypoparathyroidism in 1942 as the combined presence of hypocalcaemia and hyperphosphataemia associated with the existence of tissue resistance to parathyroid hormone (PTH) action upon normal renal function, great advances have been made in the clinical and genetic profile of patients affected by this condition. Furthermore, not only have genetic bases of pseudohypoparathyroidism been unravelled, but also variants in other genes involved in the PTH/PTHrP signalling pathway through Gsα, have been identified as the cause of diseases that share clinical features with pseudohypoparathyroidism.In the paediatric setting, the first symptoms suggesting the impairment of this signalling pathway are the presence of subcutaneous ossifications, brachydactyly and/or early onset obesity, followed by the possible development of PTH resistance. This clinical suspicion should be confirmed by an accurate molecular diagnosis to allow for coordinated multidisciplinary clinical management. Among the features of this group of disorders, physicians should pay attention to evaluation of PTH and/or thyrotropin (TSH) resistance at diagnosis and throughout follow-up, as well as growth hormone deficiency, hypogonadism, skeletal deformities, dental impairment, obesity, insulin resistance, impaired glucose tolerance or type 2 diabetes mellitus and hypertension, as well as ectopic ossifications (either subcutaneous or affecting deeper tissues) and impairment of neurocognitive development.

Pseudohypoparathyroidism (PHP) is a rare endocrine disorder derived from the defective activation of the cAMP pathway by the parathyroid hormone secondary to GNAS molecular defects. PHP subtypes are defined by the presence/absence of specific clinical/biochemical features. PHP1A is characterized by resistance to multiple hormones with features of Albright hereditary osteodystrophy (AHO), while pseudopseudohypoparathyroidism (PPHP) is characterized by AHO in the absence of PTH resistance. Small subsets of PHP and PPHP patients without known molecular defects have been re-diagnosed as being affected by the brachydactyly-mental retardation syndrome (BDMR), also known as the AHO-like syndrome. This study aimed to analyse 24 PHP1A and 51 PPHP patients without a molecular diagnosis for the presence of BDMR-associated 2q37 deletions to improve the differential diagnosis and to identify features that might help to avoid a misdiagnosis. Molecular investigations identified 4 deletions in 4 unrelated patients. The affected patients showed a combination of the most pathognomonic AHO features. Of note, 3 of the patients also displayed mild PTH resistance, and none of the patients developed ectopic ossifications. Our work confirmed the rarity of the misdiagnosis of BDMR in PHP patients through the identification of 4 patients bearing a 2q37 deletion in a cohort of 73 PHP patients (5.3%). Three patients with the deletion presented a PHP1A phenotype in the absence of any BDMR-specific findings. Further studies on larger case series are needed to elucidate the overlap between these clinical entities and to allow the early identification of patients. [ABSTRACT FROM AUTHOR]

Albright hereditary osteodystrophy (AHO) is a complex disorder defined by the presence of a short adult stature relative to the height of an unaffected parent and brachydactyly type E, as well as a stocky build, round face, and ectopic calcifications. AHO and pseudohypoparathyroidism (PHP) have been used interchangeably in the past. The term PHP describes end‐organ resistance to parathyroid hormone (PTH), occurring with or without the physical features of AHO. Conversely, pseudopseudohypoparathyroidism (PPHP) describes individuals with AHO features in the absence of PTH resistance. PHP and PPHP are etiologically linked and caused by genetic and/or epigenetic alterations in the guanine nucleotide‐binding protein alpha‐stimulating (Gsα) locus (GNAS) in chromosome 20q13. Another less‐recognized group of skeletal dysplasias, termed acrodysostosis, partially overlap with skeletal, endocrine, and neurodevelopmental features of AHO/PHP and can be overlooked in clinical practice, causing confusion in the literature. Acrodysostosis is caused by defects in two genes, PRKAR1A and PDE4D, both encoding important components of the Gsα‐cyclic adenosine monophosphate‐protein kinase A signaling pathway. We describe the clinical course and genotype of two adult patients with overlapping AHO features who harbored novel pathogenic variants in GNAS (c.2273C > G, p.Pro758Arg, NM_080425.2) and PRKAR1A (c.803C > T, p.Ala268Val, NM_002734.4), respectively. We highlight the value of expert radiological opinion and molecular testing in establishing correct diagnoses and discuss phenotypic features of our patients, including the first description of subcutaneous ossification and spina bifida occulta in PRKAR1A‐related acrodysostosis, in the context of the novel inactivating PTH/PTH related peptide signaling disorder classification system. [ABSTRACT FROM AUTHOR]

Pseudohypoparathyroidism (PHP) is a heterogeneous group of disorder with parathormone target organ resistance, characterized by hypocalcemia, hyperphosphatemia and high blood parathormone (PTH). Typical phenotypic symptoms and additional hormonal resistance can be observed in type Ia, which is also known as Albright hereditary osteodystrophy. Our patient was an eight-year and nine-month old girl with typical Albright's hereditary osteodystrophy phenotype including short stature, obesity, round face, low nasal bridge, shortened metacarpals, and mild mental retardation. In her biochemical examination, high PTH level and hypothyroidism is detected in spite of normal calcium and phosphor levels. As a result of clinic and laboratory tests, the findings were consistent with PHP type Ia with normocalcemia. In her guanine nucleotide binding protein (G protein), alpha stimulating activity polypeptide 1 (GNAS 1) gene serial analysis, C-308T>C (p1103T) transformation was detected, which was previously reported in a PHP type Ia patient. In this report, we've aimed to emphasize the fact that calcium and phosphor level in the blood of the patient with PHP type Ia can be measured normal. [ABSTRACT FROM AUTHOR]

Introduction: pseudohypoparathyroidism (PHP) is hormone resistance syndrome described for the first time in 1942 by Albright et al. All this patients had high levels of the PTH and specific skeletal deformities which were later termed as Albright hereditary osteodystrophy (AHO). The PTH requires the alpha subunit of G protein for its action. GNAS1 gene encodes the alpha subunit of the G protein and molecular defects in this gene lead to the occurrence of at least four different forms of this syndrome. Pseudopseudohypoparathyroidism (PPHP) is a form of PHP which is characterized by physical features of AHO without any evidence of PTH resistance. Albright hereditary osteodystrophy like syndrome (AHO like syndrome) has some common characteristics with AHO but is not connected with the molecular defect in the GNAS 1 gene. Case outline: we reported the case of the female patient with the phenotypic characteristics of AHO (brachydactyly, short stature, mild degree of intelectual deficit and genu varum) but without any evidence of PTH resistance. PPHP occurs mainly in families with PHP 1a and it is inherited from the father which is not the case with our patient. There is a theoretical possibility that the mutation of the GNAS 1 gene occurred de novo but without genetic testing the 2q37 deletion and AHO like syndrome can not be excluded. Conclusion: in same cases of PPHP the diagnosis of AHO like syndrome should be considered but the only way to make the precise diagnosis is the genetic testing as it was in our case.

Pseudohypoparathyroidism (PHP) is a heterogeneous group of disorder with parathormone target organ resistance, characterized by hypocalcemia, hyperphosphatemia and high blood parathormone (PTH). Typical phenotypic symptoms and additional hormonal resistance can be observed in type Ia, which is also known as Albright hereditary osteodystrophy. Our patient was an eight-year and ninemonth old girl with typical Albright's hereditary osteodystrophy phenotype including short stature, obesity, round face, low nasal bridge, shortened metacarpals, and mild mental retardation. In her biochemical examination, high PTH level and hypothyroidism is detected in spite of normal calcium and phosphor levels. As a result of clinic and laboratory tests, the findings were consistent with PHP type Ia with normocalcemia. In her guanine nucleotide binding protein (G protein), alpha stimulating activity polypeptide 1 (GNAS 1) gene serial analysis, C-308T>C (p1103T) transformation was detected, which was previously reported in a PHP type Ia patient. In this report, we've aimed to emphasize the fact that calcium and phosphor level in the blood of the patient with PHP type Ia can be measured normal. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Pseudohypoparathyroidism type Ia (PHP-Ia) is characterized by multihormone resistance and an Albright hereditary osteodystrophy (AHO) phenotype. It is caused by heterozygous mutations in GNAS gene. Clinical and biochemical findings of a female PHP-Ia patient were evaluated from age of diagnosis (6.5 years) to 14.5 years of age. The patient had short stature, brachydactyly, and subcutaneous heterotopic ossifications. Serum calcium and phosphorus levels were normal, but parathyroid hormone levels were high. Based on the typical clinical findings of AHO phenotype and biochemical findings, she was diagnosed as having PHP-Ia. A novel heterozygous mutation (c.128T>C) was found in the GNAS gene. Follow-up examinations revealed resistance to thyroid-stimulating hormone and a bioinactive growth hormone. Clinicians should take into consideration PHP-Ia in patients referred with short stature, and patients with an AHO phenotype must be further evaluated for hormone resistance, GNAS gene mutation, Gsα activity. To our knowledge, this is the first case report describing bioinactive growth hormone in PHP-Ia. [ABSTRACT FROM AUTHOR]

Background: Genetic and epigenetic alterations in the GNAS locus are responsible for the Gsa protein dysfunctions causing Pseudohypoparathyroidism (PHP) type Ia/c and Ib, respectively. For these heterogeneous diseases characterized by multiple hormone resistances and Albright's Hereditary Osteodystrophy (AHO) the current classification results inadequate because of the clinical overlap between molecular subtypes and a standard clinical approach is still missing. In the present paper several members of the Study Group Endocrine diseases due to altered function of Gsa protein of the Italian Society of Pediatric Endocrinology and Diabetology (ISPED) have reviewed and updated the clinical-molecular data of the largest case series of (epi)/genetically characterized AHO/PHP patients; they then produced a common healthcare pathway for patients with these disorders. Methods: The molecular analysis of the GNAS gene and locus identified the causal alteration in 74 subjects (46 genetic and 28 epigenetic mutations). The clinical data at the diagnosis and their evolution during up to 15 years follow-up were collected using two different cards. Results: In patients with genetic mutations the growth impairment worsen during the time, while obesity prevalence decreases; subcutaneous ossifications seem specific for this group. Brachydactyly has been detected in half of the subjects with epigenetic alterations, in which the disease overts later in life, often with symptomatic hypocalcaemia, and also early TSH and GHRH resistances have been recorded. Conclusions: A dedicated healthcare pathway addressing all these aspects in a systematic way would improve the clinical management, allowing an earlier recognition of some PHP features, the optimization of their medical treatment and a better clinical-oriented molecular analysis. Furthermore, standardized follow-up data would provide new insight into less known aspects. [ABSTRACT FROM AUTHOR]

Albright hereditary osteodystrophy (AHO) is a rare hereditary metabolic disorder that may be associated with or without resistant to parathyroid hormone (pseudohypoparathyroidism). It is commonly characterized by a constellation of physical features of short stature, round face, short neck, and small metacarpals and metatarsals, mild mental retardation, osteoporosis, subcutaneous calcification, and sometimes olfactory and hearing functional defect. Hypocalcaemia and hyperphosphatemia are the most important manifestations of the case. We report a clinical case of siblings with AHO with reduced Gs-alpha activity and we discuss their clinical features with oral manifestations, radiographic findings, laboratory tests along with treatment.

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Progressive osseous heteroplasia (POH) is a segmental disorder characterized by progressive heterotopic ossification that extends from dermal and subcutaneous tissues to deeper structures. So far, it has been taken as a rarely occurring bone disease with autosomal dominant inheritance. Here, arguments are presented in favor of the alternative concept that the disorder is merely a type 2 segmental manifestation of autosomal dominant GNAS inactivation disorders. Type 2 segmental mosaicism arises, in a heterozygous embryo, from a somatic mutational event that occurs at an early developmental stage, resulting in loss of the corresponding wild-type allele and giving rise to a homozygous or hemizygous cell clone. As a characteristic feature, such type 2 segmental involvement is far more pronounced than the type 1 segmental mosaicism as noted in otherwise healthy individuals. The concept of type 2 segmental mosaicism has been proven at the molecular level in six human traits including neurofibromatosis 1, Hailey-Hailey disease, and Gorlin syndrome. In POH, molecular proof of principle is so far lacking. The following lines of reasoning, however, support the hypothesis that POH can be explained by a similar mechanism. Firstly, POH has been found to be associated with different phenotypes caused by inactivating GNAS mutations, which is why it cannot be categorized as one distinct Mendelian trait. Secondly, POH occurs as a rather rare complication of these autosomal dominant traits, which is not compatible with the assumption of a separate Mendelian disorder. Thirdly, in a case of plate-like osteoma that represents a more superficial variant of POH, molecular proof of the concept of type 2 segmental manifestation has already been provided, and the available literature suggests that POH can be best explained by a similar mechanism. Moreover, findings obtained in animal experiments support the assumption that human POH represents such superimposed segmental manifestation of GNAS inactivation disorders. [ABSTRACT FROM AUTHOR]

2q37.3 deletion syndrome belongs to the chromosomal 2q37 deletion spectrum which clinically resembles Albright hereditary osteodystrophy (AHO) syndrome. It is is mainly characterized by short stature, obesity, round face, brachydactyly type E, intellectual disability, behavioral problems, and variable intellectual deficits. Different from classical AHO syndrome, patients with 2q37 deletion syndrome lack renal parathyroid hormone resistance (pseudohypoparathyroidism) and soft tissue ossification. So far, deletion mapping or molecular breakpoint analyses of 2q37 have been performed in only few patients. Here, we report on 2 patients with 2q37.3 deletion syndrome. In both patients the breakpoint of the 5.5-Mb terminal microdeletion could be narrowed down to the same ∼200-kb interval on 2q37.3 by BAC-FISH and/or array-CGH. Flanking low-copy repeats may indicate a classical microdeletion syndrome genesis for the 2q37.3 microdeletion subgroup. Clinical evaluation revealed intellectual deficits and type E brachydactyly typical for classical AHO syndrome together with distinctive facial dysmorphisms not present in the former. Furthermore, one patient presented with schizophrenic psychosis, an observation that would be in accordance with previous reports about an association between schizophrenia susceptibility and an unknown gene within the chromosomal region 2q37. © 2015 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

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. © 2015 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Introduction: Progressive osseous heteroplasia (POH) is a condition of invasive heterotopic ossification. Reports of patients with mild POH with Albright hereditary osteodystrophy (AHO), specifically pseudohypoparathyroidism type Ia (PHP Ia) with hormonal resistance, suggest the possibility of a common molecular basis. GNAS has been implicated to account for overlapping features of POH and PHP Ia. Case 1: A 4-year-old boy with obesity, speech delay, and expanding subcutaneous masses on buttock/forearm. Physical exam revealed round facies and brachydactyly. Blood tests showed normal Ca, P, Mg, 25-OH vitamin D levels but elevated parathyroid hormone (PTH) and thyroid-stimulating hormone (TSH). Abdominal computed tomography (CT) showed areas with calcifications in the subcutaneous tissue, fat, and muscle. Pathology of excised tissue revealed ossifications. Genomic study revealed no GNAS mutation. He had POH and PHP Ia. Case 2: A 3-year-old boy with painful ossifications in the left lower extremity. Lab tests were notable for elevated PTH and high-normal TSH. The CT-scan showed subcutaneous/intramuscular calcifications. Genetic testing showed GNAS mutation in exon 12 [c.1024C>T (R342X)]. Patient had POH and PHP Ia. Case 3: A 9-year-old boy with knee pain and subcutaneous ossifications in back and upper/lower extremity, causing significantly limited joint mobility. Lab tests were normal. The CT-scan showed areas corresponding to subcutaneous/intramuscular ossifications throughout torso and extremities, consistent with POH. There was no GNAS mutation. Conclusions: Patients with heterotopic ossifications present with a wide spectrum of disease. Although GNAS-based mutations have been postulated to account for overlapping features of AHO and POH, normal DNA studies in certain patients with POH/AHO suggest that there may exist other molecular/epigenetic mechanisms explaining their overlapping features. [ABSTRACT FROM AUTHOR]

Maternally inherited inactivating GNAS mutations are the most common cause of parathyroid hormone (PTH) resistance and Albright hereditary osteodystrophy (AHO) leading to pseudohypoparathyroidism type Ia (PHPIa) due to Gsa deficiency. Paternally inherited inactivating mutations lead to isolated AHO signs characterizing pseudo-pseudohypoparathyroidism (PPHP). Mutations are distributed throughout the Gsa coding exons of GNAS and there is a lack of genotype-phenotype correlation. In this study, we sequenced exon 1-13 of GNAS in a large cohort of PHPIa- and PPHP patients and identified 58 different mutations in 88 patients and 27 relatives. Thirty-three mutations including 15 missense mutations were newly discovered. Furthermore, we found three hot spots: a known hotspot (p.D190MfsX14), a second at codon 166 (p.R166C), and a third at the exon 5 acceptor splice site (c.435 + 1G>A), found in 15, 5, and 4 unrelated patients, respectively. Comparing the clinical features to the molecular genetic data, a significantly higher occurrence of subcutaneous calcifications in patients harboring truncating versus missense mutations was demonstrated. Thus, in the largest cohort of PHPIa patients described to date, we extend the spectrum of known GNAS mutations and hot spots and demonstrate for the first time a correlation between the genetic defects and the expression of a clinical AHO-feature. [ABSTRACT FROM AUTHOR]

ABSTRACT Pseudohypoparathyroidism type 1a ( PHP1a) is characterized by hypocalcaemia and hyperphosphatemia due to parathyroid hormone resistance, in association with the features of Albright's hereditary osteodystrophy ( AHO). PHP1a is caused by maternally inherited inactivating mutations of Gs-alpha, which is encoded by a complex imprinted locus termed GNAS. Paternally inherited mutations can lead either to pseudopseudohypoparathyroidism ( PPHP) characterized by AHO alone, or to progressive osseous heteroplasia ( POH), characterized by severe heterotopic ossification. The clinical aspects and molecular genetics of PHP1a and its related disorders are reviewed together with the 343 kindreds with Gs-alpha germline mutations reported so far in the literature. These 343 (176 different) mutations are scattered throughout the 13 exons that encode Gs-alpha and consist of 44.9% frameshift, 28.0% missense, 14.0% nonsense, and 9.0% splice-site mutations, 3.2% in-frame deletions or insertions, and 0.9% whole or partial gene deletions. Frameshift and other highly disruptive mutations were more frequent in the reported 37 POH kindreds than in PHP1a/ PPHP kindreds (97.3% vs. 68.7%, P < 0.0001). This mutation update and respective genotype-phenotype data may be of use for diagnostic and research purposes and contribute to a better understanding of these complex disorders. [ABSTRACT FROM AUTHOR]

NAS is a complex imprinted locus with multiple oppositely imprinted gene products, including the G protein α-subunit Gsα that is expressed primarily from the maternal allele in some tissues and the Gsα isoform XLαs that is expressed only from the paternal allele. Maternal Gsα mutations in mice and in patients with Albright hereditary osteodystrophy lead to obesity, insulin resistance, and hyperlipidemia. Studies in mice show that these effects are primarily due to Gsα imprinting in the central nervous system and that Gsα deficiency in one or more regions of the central nervous system lead to reduced sympathetic nervous system and energy expenditure without affecting food intake. Loss of Gsα in the central nervous system appears to lead to these effects primarily through impairment of melanocortin signaling. Loss of XLαs in mice leads to opposite effects on energy and glucose metabolism. [ABSTRACT FROM AUTHOR]