Talla baja e hipotiroidismo en un niño con Síndrome de Nail-Patella. Reporte de un caso clínico / Short stature and hypothyroidism in a child with Nail-Patella Syndrome. A case report

Resumen: Introducción: El síndrome de Nail-Patella (NPS) es un desorden autosómico dominante caracterizado por anomalías esqueléticas, displasia ungueal, alteraciones renales y oculares. El diagnóstico se sospecha con la clínica y radiología y se confirma por la identificación de una variante patogénica en el gen LMX1B. El manejo de estos pacientes implica un seguimiento continuo y el tratamiento de las posibles complicaciones ortopédicas, oculares y renales. Objetivo: Describir un caso de NPS con talla baja e hipotiroidismo, asociación que no ha sido descrita en la literatura. Caso clínico: Adolescente de 11 años con talla 130 cm (-2,01 Desviaciones Estándar [DE]) fue referido a Endocrinología a los 2 años de edad por pruebas tiroideas alteradas. Se detectaron uñas displásicas y talla baja despro porcionada, además de anormalidades radiológicas sugerentes de displasia esquelética. Se confirmó hipotiroidismo primario, con anticuerpos negativos y ecografía normal, por lo que se inició trata miento con levotiroxina. El diagnóstico de NPS fue confirmado mediante estudio genético de ADN constatándose una variante patogénica en el gen LMX1B. Su padre presentaba un fenotipo similar, con estatura normal. Su edad ósea era acorde con la cronológica. Tanto el estudio general de talla baja como un test de clonidina para estimulación de GH fueron normales. Conclusión: Presentamos un paciente con NPS confirmado, asociado a talla baja e hipotiroidismo. No hallamos publicaciones en la literatura que describieran esta triple asociación. No se descarta que podría haber una relación entre el NPS y las alteraciones tiroideas halladas en este paciente.

Abstract: Background: Nail-Patella syndrome (NPS) (OMIM: 161200) or hereditary onycho-osteodysplasia is an autosomal dominant disorder characterized by skeletal anomalies, nail dysplasia, renal and ocular abnor malities. The diagnosis is based on clinical and radiological findings and confirmed by the identification of a heterozygous pathogenic variant in the LMX1B gene. Management of these patients involves conti nuous follow-up and treatment ofthe orthopedical, ocular and renal problems that mayoccur. Objective: To describe a case of NPS with short stature and hypothyroidism, an association that has not been described in the literature. Case report: An eleven-year-old boy with a height of 130 cm (-2.01 Stan dard Deviations [SD]) was referred to the Endocrine Unit at the age of 2 years due to altered thyroid tests. At that time, dysplastic nails and disproportionate short stature were detected. Radiological abnormalities initially suggested a skeletal dysplasia. A primary hypothyroidism was confirmed, without anti-thyroid antibodies and with a normal thyroid ultrasound. Levothyroxine treatment was initiated. The diagnosis of NPS was confirmed by a genetic study with a single pathogenic variant in the LMX1B gene. His father presented a similar phenotype with normal stature. His bone age was equivalent to his chronological age. Laboratory screening for short stature and a GH stimulation test were normal. Conclusion: We present a child with proven NPS with short stature and hypothyroi dism. We did not find publications that described this triple association. It can't be ruled out that there could be a relationship between NPS and the thyroid alterations found in this patient.

Do you know this syndrome? Nail patela syndrome: a pathognomonic dermatologic finding

Abstract: The nail-patella syndrome involves a clinical tetrad of changes in the nails, knees, elbows and the presence of iliac horns. Nail changes are the most constant feature: absent, hypoplastic, or dystrophic. A pathognomonic finding is the presence of the triangular lunula. The diagnosis of nail-patella syndrome is based on clinical findings. In this paper we will discuss a case report of this syndrome and its relation with a dermatological finding.

Clinico-Genetic Study of Nail-Patella Syndrome

Nail-patella syndrome (NPS) is an autosomal dominant disease that typically involves the nails, knees, elbows and the presence of iliac horns. In addition, some patients develop glomerulopathy or adult-onset glaucoma. NPS is caused by lossof- function mutations in the LMX1B gene. In this study, phenotype-genotype correlation was analyzed in 9 unrelated Korean children with NPS and their affected family members. The probands included 5 boy and 4 girls who were confirmed to have NPS, as well as 6 of their affected parents. All of the patients (100%) had dysplastic nails, while 13 patients (86.7%) had patellar anomalies, 8 (53.3%) had iliac horns, 6 (40.0%) had elbow contracture, and 4 (26.7%) had nephropathy including one patient who developed end-stage renal disease at age 4.2. The genetic study revealed 8 different LMX1B mutations (5 missense mutations, 1 frame-shifting deletion and 2 abnormal splicing mutations), 6 of which were novel. Genotype-phenotype correlation was not identified, but inter- and intrafamilial phenotypic variability was observed. Overall, these findings are similar to the results of previously conducted studies, and the mechanism underlying the phenotypic variations and predisposing factors of the development and progression of nephropathy in NPS patients are still unknown.

Síndrome unha-patela: Evolução da instabilidade da patela / Nail-patella syndrome: evolution of pattelar instability

A síndrome da unha-patela é uma doença de caráter autossômico dominante, com algumas características clássicas dermatológicas, músculoesqueléticas e, eventualmente, renais, oculares e gastrointestinais. Tem como principal sintoma ortopédico dor patelofemoral associada com instabilidade da patela desde a primeira infância. A melhor maneira de obter bons resultados nestes casos é um tratamento precoce da instabilidade do joelho. Tratada tardiamente, pode levar a uma artrose precoce, com limitação funcional da articulação do joelho. O presente caso mostra uma paciente que, tem se apresentado com essa síndrome, foi submetida a tratamento cirúrgico tardio e evoluiu com degeneração articular e limitação funcional do joelho. O objetivo deste trabalho é atentar para as características fenotípicas sindrômicas da doença e relacioná-las com as queixas ortopédicas comuns no consultório (tais como dor e instabilidade do joelho e, possivelmente, do cotovelo) e, finalmente, poder tratar esses sintomas precocemente, garantindo uma evolução favorável para a paciente.

The nail-patella syndrome is an autosomal dominant disease with some dermatological, musculoskeletal and, occasionally, renal, ocular and gastrointestinal classical characteristics. Its main clinical orthopaedic symptom is patellofemoral pain associated with patellar instability since early childhood. The best way to achieve good results in such cases is to establish an early treatment for knee instability, otherwise it may lead to early arthrosis and functional limitation of the knee joint. The present case describes a patient with such syndrome who underwent late surgical treatment and evolved with joint degeneration and functional limitation of the knee. The objective of this study is to consider the syndromic phenotypic features of the disease, correlate them with orthopaedic complaints commonly reported to the physician, such as pain and instability of the knee joint and maybe of the elbow joint and, finally, be able to provide an early treatment for symptoms in order to ensure a favorable evolution to the patient.

Afectación renal en el síndrome onico-patelar / Renal involvement in the onycho-patellar syndrome

El síndrome onico-patelar es un cuadro genético autosómico dominante con una expresividad variable que afecta tejido de origen ectodérmico y mesodérmico. Es poco frecuente y se caracteriza por una tetrada: alteraciones ungueales, lúnula triangular, rótula hipoplásica o ausente, artrodisplasia de codo y cuernos ilíacos. Motiva esta presentación la observación de pacientes con afectación renal, haciendo una revisión bibliográfica en este sentido

Nail-patella syndrome with some unusual features.

Nail-patella syndrome is a rare hereditary disease. We report a patient who was the lone member affected in the family. The patient additionally had a bony defect of the skull which has not been reported so far in the literature.