Diagnostic challenges in hypophosphatasia in adult patients / Desafios do diagnóstico da hipofosfatasia em adultos

Introdução: Hipofosfatasia é um distúrbio metabólico que afeta a mineralização óssea e dentária, causada por mutações no gene ALPL, levando à deficiência enzimática da fosfatase alcalina tecido não-específica. A forma adulta caracteriza-se por fraturas atípicas do fêmur, osteomalácia, osteoporose, grave osteoartropatia, condrocalcinose e artralgia. Objetivo: Demonstrar desafios diagnósticos relacionados à hipofosfatasia através do relato de dois casos. Paciente 1: feminino, 59 anos, encaminhada para avaliação clínica devido às fraturas patológicas de difícil consolidação e osteoporose generalizada de causa genética. Relata perda dentária precoce da arcada superior, fraturas na coluna, em ombro esquerdo e no fêmur. Atualmente, queixa-se de dor crônica intensa, com uso de múltiplos medicamentos. Achados clínicos, laboratoriais e radiológicos foram compatíveis com o diagnóstico de hipofosfatasia. Paciente 2: masculino, 31 anos, filho da paciente 1, encaminhado para avaliação clínica por fratura patológica precoce em fêmur esquerdo e osteoporose não esclarecida. Atualmente relata dor e claudicação importante em membro inferior esquerdo, associado à lombalgia crônica. Confirmação do diagnóstico de hipofosfatasia por exames laboratoriais e radiológicos e sequenciamento do gene ALPL, aliados ao diagnóstico da sua genitora. Discussão: Hipofosfatasia é uma doença rara de herança autossômica dominante e recessiva. Pacientes acometidos apresentam fraturas constantes, densidade mineral óssea baixa, cicatrização óssea deficitária. É comum a hipofosfatasia ser diagnosticada erroneamente como osteopenia e/ou osteoporose primária, acarretando prejuízos ao paciente. Ressalta-se a importância da história clínica completa e dos antecedentes familiares a fim de se obter um diagnóstico precoce, garantindo, por sua vez, o adequado acompanhamento e manejo terapêutico (AU)

Introduction: hypophosphatasia is a metabolic disorder affecting bone and tooth mineralization, caused by mutations in the ALPL gene leading to enzymatic deficiency of tissue non-specific alkaline phosphatase. The adult form is characterized by atypical femur fractures, osteomalacia, osteoporosis, severe osteoarthropathy, chondrocalcinosis, and arthralgia. Objective: to demonstrate diagnostic challenges related to hypophosphatasia through the report of two cases. Patient 1: female, 59 years old, referred for clinical evaluation due to pathological fractures of difficult consolidation and generalized osteoporosis of genetic cause. She reports early tooth loss in the upper arch, fractures in the spine, left shoulder and femur. Currently, he complains of severe chronic pain, with use of multiple medications. Clinical, laboratory, and radiological findings were compatible with the diagnosis of hypophosphatasia. Patient 2:male, 31 years old, son of patient 1, referred for clinical evaluation due to an early pathological fracture in the left femur and unclear osteoporosis. He currently reports pain and significant claudication in the left lower limb, associated with chronic low back pain. Confirmation of the diagnosis of hypophasatasia by laboratory and radiological tests and sequencing of the ALPL gene combined with the diagnosis of his mother. Discussion: hypophosphatasia is a rare disease of autosomal dominant and recessive inheritance. Affected patients have constant fractures, low bone mineral density, and impaired bone healing. It is common for hypophosphatasia to be misdiagnosed as osteopenia and/or primary osteoporosis, which can be harmful to the patient. The importance of a complete clinical history and family history is emphasized in order to obtain an early diagnosis, ensuring adequate follow-up and therapeutic management (AU)

Un caso de hipofosfatasia perinatal grave con una mutación novedosa / Severe perinatal hypophosphatasia case with a novel mutation

La hipofosfatasia es un trastorno hereditario raro causado por mutaciones en el gen ALPL. Causa defectos en la mineralización ósea y dental, función respiratoria anormal, convulsiones, hipotonía, dolor óseo y nefrocalcinosis. Las formas clínicas se reconocen según la edad al diagnóstico y la gravedad. Presentamos el caso de una lactante con fontanela anterior agrandada, bóveda craneal blanda, fracturas, dificultad respiratoria y convulsiones. El análisis bioquímico mostró hipercalcemia, fosfato sérico normal y fosfatasa alcalina sérica baja. La radiografía mostró hipomineralización, fracturas y callos. La concentración plasmática de piridoxal-5'-fosfato era de 762 mg/l (intervalo normal: 5-50) y la concentración de fosfoetanolamina en orina era de 1015 mmol/l (intervalo normal: 15-341). El análisis del gen ALPL mostró dos mutaciones heterocigotas compuestas, una de las cuales es novedosa. El diagnóstico y tratamiento tempranos de la hipofosfatasia perinatal podría mejorar los resultados y tener un impacto positivo en la sobrevida.

Hypophosphatasia (HPP) is a rare inherited disorder caused by mutations in the ALPL gene. Mineralization defect in bones and teeth, abnormal respiratory function, seizures, hypotonia, bone pain, and nephrocalcinosis can be observed. Clinical forms are usually recognized based on age at diagnosis and severity of features. We present an infant with an enlarged anterior fontanelle, soft calvarium, fractures, respiratory distress, and seizures. Biochemical analysis showed hypercalcemia, normal serum phosphate, and low serum alkaline phosphatase (ALP) levels. X-ray showed hypomineralization, fractures, and callus formations. Plasma pyridoxal 5'-phosphate (PLP) was 762 mg/L (NV : 5-50) and urine phosphoethanolamine (PEA) was 1015 mmol/L (NV : 15-341) and ALPL gene analysis showed two compound heterozygous mutations, one of which is a novel one. Early diagnosis and treatment of perinatal HPP may improve outcomes and might have a positive impact on survival.

Desafios do diagnóstico da hipofosfatasia em adultos / Diagnostic challenges in hypophosphatasia in adult patients

RESUMO:Introdução: Hipofosfatasia é um distúrbio metabólico que afeta a mineralização óssea e dentária, causada por mutações no gene ALPL, levando à deficiência enzimática da fosfatase alcalina tecido não-específica. A forma adulta caracteriza-se por fraturas atípicas do fêmur, osteomalácia, osteoporose, grave osteoartropatia, condrocalcinose e artralgia. Objetivo: Demonstrar desafios diagnósticos relacionados à hipofosfatasia através do relato de dois casos. Paciente 1: feminino, 59 anos, encaminhada para avaliação clínica devido às fraturas patológicas de difícil consolidação e osteoporose generalizada de causa genética. Relata perda dentária precoce da arcada superior, fraturas na coluna, em ombro esquerdo e no fêmur. Atualmente, queixa-se de dor crônica intensa, com uso de múltiplos medicamentos. Achados clínicos, laboratoriais e radiológicos foram compatíveis com o diagnóstico de hipofosfatasia. Paciente 2: masculino, 31 anos, filho da paciente 1, encaminhado para avaliação clínica por fratura patológica precoce em fêmur esquerdo e osteoporose não esclarecida. Atualmente relata dor e claudicação importante em membro inferior esquerdo, associado à lombalgia crônica. Confirmação do diagnóstico de hipofosfatasia por exames laboratoriais e radiológicos e sequenciamento do gene ALPL, aliados ao diagnóstico da sua genitora. Discussão: Hipofosfatasia é uma doença rara de herança autossômica dominante e recessiva. Pacientes acometidos apresentam fraturas constantes, densidade mineral óssea baixa, cicatrização óssea deficitária. É comum a hipofosfatasia ser diagnosticada erroneamente como osteopenia e/ou osteoporose primária, acarretando prejuízos ao paciente. Ressalta-se a importância da história clínica completa e dos antecedentes familiares a fim de se obter um diagnóstico precoce, garantindo, por sua vez, o adequado acompanhamento e manejo terapêutico. (AU)

ABSTRACT: Introduction: hypophosphatasia is a metabolic disorder affecting bone and tooth mineralization, caused by mutations in the ALPL gene leading to enzymatic deficiency of tissue non-specific alkaline phosphatase. The adult form is characterized by atypical femur fractures, osteomalacia, osteoporosis, severe osteoarthropathy, chondrocalcinosis, and arthralgia. Objective: to demonstrate diagnostic challenges related to hypophosphatasia through the report of two cases. Patient 1: female, 59 years old, referred for clinical evaluation due to pathological fractures of difficult consolidation and generalized osteoporosis of genetic cause. She reports early tooth loss in the upper arch, fractures in the spine, left shoulder and femur. Currently, he complains of severe chronic pain, with use of multiple medications. Clinical, laboratory, and radiological findings were compatible with the diagnosis of hypophosphatasia. Patient 2:male, 31 years old, son of patient 1, referred for clinical evaluation due to an early pathological fracture in the left femur and unclear osteoporosis. He currently reports pain and significant claudication in the left lower limb, associated with chronic low back pain. Confirmation of the diagnosis of hypophasatasia by laboratory and radiological tests and sequencing of the ALPL gene combined with the diagnosis of his mother. Discussion: hypophosphatasia is a rare disease of autosomal dominant and recessive inheritance. Affected patients have constant fractures, low bone mineral density, and impaired bone healing. It is common for hypophosphatasia to be misdiagnosed as osteopenia and/or primary osteoporosis, which can be harmful to the patient. The importance of a complete clinical history and family history is emphasized in order to obtain an early diagnosis, ensuring adequate follow-up and therapeutic management. (AU)

Active search of adult patients with persistently low serum alkaline phosphatase levels for the diagnosis of hypophosphatasia

ABSTRACT Objectives: Alkaline phosphatase (ALP) is the main laboratory marker of hypophosphatasia (HPP), a rare disease unknown to most physicians. The prevalence of HPP has been widely discussed in the literature due to the diverse phenotypes of HPP. The purpose of this study was to search for patients with hypophosphatasemia based on previous biochemistry tests and reevaluate them to confirm the diagnosis of HPP. Subjects and methods: A total of 289,247 biochemical tests for ALP in adults were performed from 2015 to 2019 in two tertiary hospitals in Rio de Janeiro were reviewed (Clementino Fraga Filho University Hospital - HUCFF - and Bonsucesso Federal Hospital - BFH). Results: A total of 1,049 patients were identified with ALP levels below 40 U/L, and 410 patients had hypophosphatasemia confirmed by at least two exams. After the active search of medical reports and/or interviews based on structured questionnaires, 398 subjects were excluded due to secondary causes of reduced ALP. The remaining 12 patients were invited to attend the medical consultation at HUCFF, accompanied by at least one first-degree relative. None of the patients or their relatives had a history or clinical manifestations consistent with HPP. Serum ALP was within reference values in all relatives, but persistently low in further laboratory evaluation in all the 12 patients, in whom secondary causes were ruled out. Thus, we cannot exclude the possibility that they might carry the mutations associated with HPP. Conclusion: Further image evaluations and genetic testing would be appropriate to confirm this asymptomatic adult form of HPP.

Hipofosfatasemia crónica persistente de causa no determinada y su repercusión músculo-esquelética / Persistent hypophosphatasemia and its musculoskeletal repercussion

La fosfatasa alcalina baja o hipofosfatasemia, ya sea debida a causas genéticas (hipofosfatasia) o secundarias, presenta correlato clínico. Nuestro objetivo es estimar la prevalencia de hipofosfatasemia crónica persistente y describir sus hallazgos osteometabólicos. Se realizó una búsqueda electrónica de afiliados adultos al Hospital Italiano de Buenos Aires, entre 2013 y 2017, con al menos 2 determinaciones de fosfatasa alcalina igual a 30 UI/l o menor y ninguna mayor de 30 UI/l (rango de referencia 30-100 UI/l). Se excluyeron aquellos con causas secundarias diagnosticadas y se analizaron los correlatos clínico y bioquímico. Se detectó hipofosfatasemia crónica persistente en 78 de 105.925, 0,07% (0,06-0,09) de los afiliados. Solo uno fue excluido por tener causa secundaria. Eran 61,1% mujeres de 44 (34-56) años, fosfatasa alcalina 24 (20-27) UI/L, fosfatemia 4,1 (3,8-4,6) mg/dl. Se observaron osteoartritis, calcificaciones vasculares y fracturas, menos frecuentemente litiasis renal, calcificación del ligamento longitudinal común anterior, pérdida dental y convulsiones. El 63,6% tenían al menos una de las características clínico-radiológicas evaluadas, pero en solo 5,2% fue mencionado el diagnóstico de hipofosfatasemia en la historia clínica. La densitometría evidenció algún grado de afección (osteopenia u osteoporosis) en 76,2%. Se constataron 19 fracturas, con predominio en radio. La prevalencia de hipofosfatasemia fue similar a lo previamente reportado. El reconocimiento fue bajo; sin embargo, se observaron variadas manifestaciones músculo-esqueléticas, similares a las descriptas en la hipofosfatasia del adulto, por lo cual ­ante una hipofosfatasemia sin causa secundaria­ se sugiere considerar este diagnóstico. (AU)

Low alkaline phosphatase (ALP) or hypophosphatasemia either due to genetic (hypophosphatasia) or secondary causes, presents a clinical correlate. Our objectives are to estimate the prevalence of persistent hypophosphatasemia and to describe the clinical findings. We performed a search using the electronic medical records of the members of the Hospital Italiano de Buenos Aires health care system, between 2013 and 2017. Adult members with ≥ 2 ALP ≤ 30 IU/l, no ALP >30 IU/l (normal range 30-100 UI/l) and without diagnosed secondary causes were analyzed. Persistent hypophosphatasemia was detected in 78 of 105.925, 0.07% (0.06-0.09) of members. Only one was excluded due to a secondary cause, 61.1% were women, 44 (34-56) year-old, ALP 24 (20-27) IU/l and phosphatemia 4.1 (3.8-4.6) mg/dl. Osteoarthritis, vascular calcifications and fractures were detected, and nephrolithiasis, DISH (Diffuse idiopathic skeletal hyperostosis), tooth loss, and seizures were less frequently observed. At least one of the mentioned characteristics were present in 63.6 %, but only 5.2% had hypophosphatasemia registered in their clinical record. Densitometry showed osteopenia or osteoporosis in 76.2%. There were 19 fractures, most of them in radius. The prevalence of hypophosphatasemia was similar to what has been previously reported. Hypophosphatasemia finding in medical records was low, but far from being asymptomatic, clinical manifestations were observed. In the presence of hypophosphatasemia without a secondary cause, adult hypophosphatasia should be uspected. (AU)

Caso clínico: hipofosfatasia de la niñez. Seguimiento clínico / Clinical case: childhood hypophosphatasia. Clinical follow-up

La hipofosfatasia (HP) es una enfermedad congénita, causada por mutaciones con pérdida de función en el gen ALPL que codifica la isoenzima no específica de tejido de la fosfatasa alcalina (TNSALP). Su expresión clínica es muy variable, desde casos de muerte intraútero por alteración grave de la mineralización ósea, hasta casos solo con caída prematura de la dentición. Se presenta el caso clínico de un varón al que se le diagnosticó odontohipofosfatasia a los 30 meses por pérdida temprana de piezas dentarias y niveles anormalmente bajos de fosfatasa alcalina, sin signos de raquitismo ni deformidades óseas. Durante su seguimiento, hasta los 13 años, presentó síntomas compatibles con HP infantil leve, como cansancio al caminar, incoordinación en la marcha y dolor en miembros inferiores que aumentaban con la actividad física. Ante la aparición de edema bimaleolar y poca respuesta al tratamiento con calcitonina y antiinflamatorios, se descartaron patologías infecciosas o reumáticas o ambas y se diagnosticó, por biopsia de tibia y peroné, periostitis sin detección de cristales de pirofosfato. Los controles radiológicos durante su evolución mostraron ensanchamiento metafisario en muñeca, falta de remodelado de metacarpianos, hojaldrado perióstico en tibia y peroné e hipomineralización en metáfisis tibiales, con "lenguas radiolúcidas" características de HP. Como conclusión, la hipofosfatasia debe considerarse como una entidad clínica para descartar en niños que presentan pérdida temprana de dientes. La presencia de este cuadro clínico es en general suficiente para realizar el diagnóstico de HP de la niñez. (AU)

Hypophosphatasia (HP) is a congenital disease, caused by mutations with loss of function in the gene ALPL that encodes the non-specific tissue isoenzyme of alkaline phosphatase (TNSALP). Its clinical expression displays considerable variability, from cases of intrauterine death due to severe alteration of bone mineralization, to cases with only early loss of teeth. We report the case of a male, diagnosed as odontohypophosphatasia at 30 months of age due to early loss of teeth and abnormally low levels of alkaline phosphatase, without signs of rickets or bone deformities. During follow-up, up to 13 years of age, he presented symptoms consistent with mild infantile HP such as tiredness when walking, lack of gait coordination, and pain in lower limbs, especially after physical activity. Due to the appearance of bimalleolar edema and poor response to treatment with calcitonin and anti-inflammatory drugs, infectious and / or rheumatic pathologies were ruled out. Periostitis without pyrophosphate crystal detection was diagnosed by tibial and fibular biopsy. Radiological controls during follow up showed metaphyseal wrist enlargement, lack of remodeling of metacarpals, periosteal flaking in the tibia and fibula and hypomineralization in the tibial metaphysis, with "radiolucent tongues"; characteristic of HP. In conclusion, hypophosphatasia should be considered as a clinical entity in children who present early loss of teeth. The presentation of this clinical case is generally sufficient to make the diagnosis of childhood HP. (AU)

Manifestaciones maxilofaciales del raquitismo hipofosfatémico: reporte de un caso clínico / Maxillofacial manifestations of hypophosphatemic rickets: report of a clinical case

El raquitismo hipofosfatémico es una alteración metabólica transmitida genéticamente (ligada al cromosoma X) en donde disminuye la reabsorción de fosfato en el túbulo proximal. Esta enfermedad se manifiesta con defectos en la mineralización de los tejidos esquelético y dentario. El caso clínico presentado en este artículo corresponde a un niño de 8 años de edad con eta alteración en la que se observan deformidades en las extremidades inferiores (piernas arqueadas), disminución de su talla y bucalmente en los tejidos blandos, se aprecia gingivitis generalizada y sondajes periodontales no mayores de 2 mm. En el aspecto dentario existe una relación molar en clase II de Angle, con pérdida prematura de los molares temporales y por consecuencia, erupción prematura de los premolares permanentes. Debido a la asociación con la deficiente formación dentaria y la historia familiar, podríamos suponer una asociación entre raquitismo hipofosfatémico y las periodontitis de inicio precoz

Pseudohypophosphatasia.

Two rare cases of pseudohypophosphatasia in two siblings which so far, to best of our knowledge have not been reported.

Hipofosfatasia en un lactante: a propósito de un caso / Hypophosphatasia in an infant: apropos of a case report

Se presenta un caso de hipofosfatasia en un lactante de sexo masculino. Se confirmó el diagnóstico por presentar un raquitismo con fosfatasas alcalinas séricas disminuídas y fosfoetanolamina en orina elevada. Se describen sus características, posible tratamiento con sobrecarga de fosfato oral y se analiza su pronóstico