Deficiencia de vitamina D en la edad adulta: presentación de 2 casos familiares de seudohipoparatiroidismo / Vitamin D deficiency in adulthood: Presentation of 2familial cases simulating pseudohypoparathyroidism

Antecedentes y objetivo El solapamiento clínico y bioquímico de diversas enfermedades del metabolismo fosfocálcico puede conllevar un erróneo diagnóstico y su consecuente abordaje clínico. Un ejemplo es el seudohipoparatiroidismo, que puede confundirse con el raquitismo dependiente de vitamina D (VDDR1) si no se hacen las determinaciones bioquímicas adecuadas. Pacientes y métodos Dos parejas de hermanos, de familias independientes, fueron diagnosticados clínicamente en la adolescencia de seudohipoparatiroidismo al presentar hipocalcemia, niveles elevados de hormona paratiroidea y valores normales o elevados de fósforo. Tras descartar alteraciones en GNAS, se realizó un estudio, mediante secuenciación masiva, de genes asociados a otros diagnósticos diferenciales. Resultados Se identificaron 2variantes genéticas en el gen CYP27B1 potencialmente asociadas con el fenotipo. Variantes patogénicas en este gen se asocian con VDDR1A. La reevaluación clínica-bioquímica de los pacientes confirmó dicho diagnóstico y se adecuó el tratamiento. Conclusiones Si bien la VDDR1A es un trastorno del metabolismo de diagnóstico infrecuente en la edad adulta, en casos de hipocalcemia con valores elevados de PTH es relevante la determinación de las formas 1,25(OH)2D3 y 25(OH)D3 de la vitamina D para alcanzar un diagnóstico correcto (AU)

Background and objective The clinical and biochemical overlap of various pathologies of phosphocalcic metabolism can lead to misdiagnosis and consequent clinical management. One example is pseudohypoparathyroidism, which can be confused with vitamin D-dependent rickets (VDDR1) if appropriate biochemical determinations are not performed. Patients and methods Two pairs of siblings, from independent families, were clinically diagnosed in adolescence with pseudohypoparathyroidism due to hypocalcaemia, elevated parathyroid hormone levels and normal or elevated phosphorus values. After ruling out alterations in GNAS, a massive sequencing study of genes associated with other differential diagnoses was carried out. Results Two genetic variants in the CYP27B1 gene potentially associated with the phenotype were identified. Pathogenic variants in this gene are associated with VDDR1A. Clinical-biochemical re-evaluation of the patients confirmed this diagnosis and treatment was adapted. Conclusions Although VDDR1A is an infrequently diagnosed pathology in adulthood, in cases of hypocalcaemia with elevated PTH values, determination of the 1,25(OH)2D3 and 25(OH)D3 forms of vitamin D is relevant to reach a correct diagnosis (AU)

Nutrition recommendations for patients with pseudohypoparathyroidism.

Pseudohypoparathyroidism (PHP) is a spectrum of diseases characterized by insensitivity of target tissues to the action of parathyroid hormone and, consequently, by the presence of hyperphosphatemia and hypocalcaemia of varying severity. Early-onset obesity is a feature of PHP type 1A. This article discusses the need to establish uniform criteria to guide the nutritional management of patients with PHP. A decrease in energy expenditure calls for an adjustment of the energy content of the diet. Reducing the intake of foods rich in inorganic phosphorus helps to manage hyperphosphataemia. Targeted nutrition should be part of the treatment plan of children and adolescents with PHP, since it contributes to modulating the calcium and phosphorus metabolism imbalances characteristic of these patients.

[Vitamin D deficiency in adulthood: Presentation of 2familial cases simulating pseudohypoparathyroidism]. / Deficiencia de vitamina D en la edad adulta: presentación de 2 casos familiares de seudohipoparatiroidismo.

BACKGROUND AND OBJECTIVE: The clinical and biochemical overlap of various pathologies of phosphocalcic metabolism can lead to misdiagnosis and consequent clinical management. One example is pseudohypoparathyroidism, which can be confused with vitamin D-dependent rickets (VDDR1) if appropriate biochemical determinations are not performed. PATIENTS AND METHODS: Two pairs of siblings, from independent families, were clinically diagnosed in adolescence with pseudohypoparathyroidism due to hypocalcaemia, elevated parathyroid hormone levels and normal or elevated phosphorus values. After ruling out alterations in GNAS, a massive sequencing study of genes associated with other differential diagnoses was carried out. RESULTS: Two genetic variants in the CYP27B1 gene potentially associated with the phenotype were identified. Pathogenic variants in this gene are associated with VDDR1A. Clinical-biochemical re-evaluation of the patients confirmed this diagnosis and treatment was adapted. CONCLUSIONS: Although VDDR1A is an infrequently diagnosed pathology in adulthood, in cases of hypocalcaemia with elevated PTH values, determination of the 1,25(OH)2D3 and 25(OH)D3 forms of vitamin D is relevant to reach a correct diagnosis.

Pseudohypoparathyroidism: an endocrine orphan disease. case report

Introduction: Pseudohypoparathyroidism (PHP) is a heterogeneous group of rare endocrine disorders characterized by resistance to the parathyroid hormone. There are few reports on PHP in Colombia, so the publication of the present case contributes to increase the interest in its research in the clinical setting. Case presentation: An 18-year-old male with a history of hypothyroidism diagnosed at 4 months of age, stunted growth, delayed puberty, obesity, brachydactyly, pathologic fractures, femoral osteochondroma, insomnia, paresthesia, and chronic constipation was referred to the endocrinology service of a tertiary care center in Bogotá (Colombia) after being hospitalized following a seizure episode. On admission, laboratory tests revealed hypocalcemia, hyperphosphatemia, 25-hydroxy vitamin D in the range of insufficiency and elevated PTH. Imaging studies showed heterotopic ossifications and calcifications of the basal ganglia. A genetic study confirmed the diagnosis of PHP1A, so treatment was started with calcium, cholecalciferol and phosphorus chelators, leading to a satisfactory course. Both the patient and his first-degree relatives received genetic counseling and interdisciplinary assessment. Conclusion: Although PHP type 1A is an unrecognized complex genetic disorder, it has a critical clinical importance within the differential diagnoses of hypocalcemia. Without prompt diagnosis and treatment, patients may experience serious and potentially fatal metabolic consequences.

Introducción. El seudohipoparatiroidismo (SPT) es un trastorno genético poco frecuente que se caracteriza por la resistencia a la hormona paratiroidea (PTH). En Colombia existen pocos reportes sobre esta enfermedad, por lo que la publicación del presente caso contribuye a aumentar el interés en su búsqueda en el ámbito clínico. Presentación del caso. Hombre de 18 años con antecedente de hipotiroidismo (diagnosticado a los 4 meses de nacido), retraso del crecimiento, desarrollo puberal tardío, obesidad, braquidactilia, fracturas patológicas, osteocondroma femoral, insomnio, parestesias y estreñimiento crónico, quien asistió al servicio de endocrinología de un hospital de tercer nivel de Bogotá (Colombia) remitido luego de haber estado hospitalizado por un episodio convulsivo. En dicha hospitalización los laboratorios evidenciaron hipocalcemia, hiperfosfatemia y 25-OH vitamina D en rango de insuficiencia con niveles elevados de PTH, y los estudios imagenológicos demostraron osificaciones heterotópicas y calcificaciones de ganglios basales del cerebro. Al paciente se le realizó un estudio genético que confirmó el diagnóstico de SPT1A, por lo que se le inició manejo con suplencia de calcio, colecalciferol y quelantes de fósforo, con lo cual evolucionó satisfactoriamente. Tanto el paciente como sus familiares de primer grado recibieron asesoramiento y valoración interdisciplinaria. Conclusiones. El SPT1A es un trastorno genético complejo poco conocido pero de alta importancia clínica dentro de los diagnósticos diferenciales de hipocalcemia que debe considerarse ya que sin el diagnóstico y tratamiento oportunos, los pacientes pueden presentar consecuencias metabólicas graves y potencialmente fatales.

Deficiencia de vitamina D asociada a hiperfosfatemia en niños / Vitamin D deficiency associated with hyperphosphatemia in children

RESUMEN Los niños con deficiencia de vitamina D pueden tener fósforo normal o alto a pesar de tener una prueba de hormona paratiroidea (PTH) elevada. El pseudohipoparatiroidismo (PHP) se caracteriza por cursar con hiperfosfatemia. La similitud que puede ocurrir entre la deficiencia de vitamina D asociada a hiperfosfatemia y el PHP hace importante revisar reportes de casos de deficiencia de vitamina D asociada a hiperfosfatemia para entender por qué puede ocurrir esta asociación y cuál es la relevancia de estudiar el nivel de vitamina D en niños con sospecha de PHP. El objetivo de esta revisión fue identificar reportes de niños con deficiencia de vitamina D asociada a hiperfosfatemia y discutir los mecanismos de esta asociación. Se identificaron reportes de 7 casos en niños. La deficiencia de vitamina D reduciría la respuesta fosfatúrica ante una PTH elevada. Se concluye que es importante descartar deficiencia de vitamina D en todo niño con sospecha de PHP.

ABSTRACT Children with vitamin D deficiency can have normal or high phosphorus despite having a high parathyroid hormone test (PTH). Pseudohypoparathyroidism (PHP) is characterized by hyperphosphatemia. The similarity that can occur between vitamin D deficiency associated with hyperphosphatemia and PHP makes it important to review case reports of vitamin D deficiency associated with hyperphosphatemia to understand why this association may occur and what is the relevance of studying the vitamin D level in children with suspected PHP. The aim of this review was to identify reports of children with vitamin D deficiency associated with hyperphosphatemia and to discuss the mechanisms of this association. Reports of 7 children cases were identified. Vitamin D deficiency could reduce the phosphaturic response to elevated PTH. It is concluded that it is important to rule out vitamin D deficiency in all children with suspected PHP.

Seudohipoparatiroidismo 1b / Pseudohypoparathyroidism 1b

RESUMEN El seudohipoparatiroidismo 1b se caracteriza por resistencia aislada a la parathormona, en ausencia de las manifestaciones típicas de la osteodisfrofia hereditaria de Albright; debido a alteraciones epigenéticas del locus GNAS. Puede presentarse de forma esporádica, o heredado de manera autosómico dominante por vía materna. Se presenta paciente masculino de 31 años, con antecedentes de tumores óseos y calcificaciones cerebrales diagnosticados a los 14 años; que se consulta por presentar mareo intenso, rigidez del cuello y la boca, dificultad para hablar y tragar, desorientación y trastornos de percepción; con fenotipo y somatometría normales, y signos de tetania latente (Chvostek y Trouseau positivos). Los estudios realizados mostraron: hipocalcemia, hiperfosfatemia, aumento de niveles de parathormona y múltiples calcificaciones en cerebro y cerebelo. Con tales hallazgos se emite el diagnóstico de seudohipoparatiroidismo 1b, el cual se confirma mediante pruebas moleculares con alteración en el patrón de metilación en el locus GNAS. No presentó alteraciones en el estudio de secuenciación de los 13 exones codificantes del GNAS. Se concluyó como un caso esporádico ante la ausencia de historia familiar de hipocalcemia, combinado con amplia pérdida de metilación del gen GNAS y la no evidencia de deleciones. Se presenta el primer reporte de esta enfermedad en Cuba con estudio molecular(AU)

ABSTRACT Pseudohypoparathyroidism 1b is characterized by isolated resistance to parathormone, in the absence of the typical manifestations of hereditary Albright osteodysphrophy; due to epigenetic alterations of the GNAS locus. It can occur sporadically, or inherited in an autosomal dominant way through the mother. We report the case of a 31-year-old male patient, with history of bone tumors and cerebral calcifications diagnosed at age 14. She came to consultation due to severe dizziness, stiff neck and mouth, difficulty speaking and swallowing, disorientation and perception disorders; he showed normal phenotype and somatometry, and signs of latent tetany (positive Chvostek and Trouseau). Studies have shown hypocalcaemia, hyperphosphatemia, increased levels of parathormone and multiple calcifications in the brain and cerebellum. These findings, pseudohypoparathyroidism 1b is diagnosed confirmed by molecular tests showing alteration in the methylation pattern in the GNAS locus. There were no alterations in the sequencing study of the 13 exons coding for GNAS. It was concluded as a sporadic case in the absence of a family history of hypocalcemia, combined with extensive loss of GNAS gene methylation and no evidence of deletions. This is the first report this disease with molecular study in Cuba(AU)

Late diagnosis of pseudohypoparathyroidism in adulthood. Case series / Pseudohipoparatiroidismo diagnosticado tardíamente en la adultez, una serie de casos

Abstract Introduction: Pseudohypoparathyroidism (PHP) is a rare hereditary disease, characterized by hypocalcemia/hyperphosphatemia secondary to peripheral resistance to parathyroid hormone (PTH). PHP diagnosis is usually precluded since hypocalcemia is considered as the primary diagnosis, thus delaying further diagnostic studies and preventing an adequate management of this clinical condition. Materials and methods: Retrospective review of the databases of the Endocrinology departments of two tertiary care centers of Medellin, Colombia from January 2012 to December 2016. Patients diagnosed with PHP based on clinical presentation and confirmatory laboratory values were included. Results: Four patients met the inclusion criteria. All PHP cases were diagnosed in adulthood despite strong early clinical and laboratory evidence of the disease. Three patients were diagnosed with Fahr's syndrome and two with Albright's hereditary osteodystrophy. The mean values obtained were PTH of 376.8 pg/mL, calcium of 6.17 mg/dL and phosphorus of 6.55 mg/dL. Conclusions: PHP is a rare disorder. This paper describes four PHP cases diagnosed during adulthood. Emphasis should be placed on the judicious approach to the patient with hypocalcemia and hyperphosphatemia with increased PTH and normal renal function, since these symptoms strongly suggest a diagnosis of PHP.

Resumen Introducción. El pseudohipoparatiroidismo (PHP) es una condición rara caracterizada por hipocalcemia e hiperfosfatemia secundarias a resistencia periférica a la hormona paratiroidea (PTH). Es frecuente que la hipocalcemia sea establecida de forma equivocada como diagnóstico primario y que el diagnóstico definitivo de PHP sea tardío, difiriendo los estudios y el manejo específico que exigen estos pacientes. Materiales y métodos. Se revisaron de forma retrospectiva las bases de datos de endocrinología de dos centros terciarios de Medellín, Colombia, desde enero de 2012 a diciembre de 2016. Se incluyeron pacientes con diagnóstico de PHP por presentación clínica y valores confirmatorios de laboratorio. Resultados. Cuatro pacientes cumplieron los criterios de inclusión. Todos los casos fueron diagnosticados en la adultez a pesar de tener evidencia temprana, clínica y bioquímica de la enfermedad. Tres pacientes tenían síndrome de Fahr y dos tenían osteodistrofia hereditaria de Albright. Los valores medios registrados fueron PTH de 376.8 pg/mL, calcio de 6.17 mg/dL y fósforo de 6.55 mg/dL. Conclusiones. El PHP es un trastorno raro; se describen cuatro casos diagnosticados de forma tardía en la adultez. Se enfatiza en el enfoque juicioso del paciente con hipocalcemia, la cual, en presencia de hiperfosfatemia con PTH elevada y función renal normal, debe hacer sospechar el diagnóstico de PHP.

[Clinical features of two cases of pseudohypoparathyroidism (ia and ib) and molecular analysis of GNAS]. / Aspectos clínicos en dos casos de seudohipoparatiroidismo (ia y ib) y estudio molecular del locus GNAS.

Pseudohypoparathyroidism (PHP) is a rare disorder, characterized by a tissue resistance to parathyroid hormone (PTH). The two main subtypes of PHP, PHPIa and PHPIb, are caused by alterations in the GNAS locus (20q13.3), which encodes the Gsα protein, essential for the action of PTH and other hormones. PHP-Ia is associated with several hormone resistances, Albright hereditary osteodystrophy (AHO), and reduced Gsα activity. It is caused by inactivating mutations in the GNAS gene. PHP-Ib presents with isolated resistance to PTH, without AHO and with normal to low Gsα activity. It is related to imprinting defects in GNAS. Two unrelated cases of PHP-Ia and PHP-Ib are presented here, focusing on their clinical aspects and in the differential diagnosis with similar pathologies.