Afectación respiratoria en paciente con acrodisostosis: una asociación infrecuente de una enfermedad rara / Respiratory impairment in a patient with acrodysostosis: A rare association of an uncommon pathology

La acrodisostosis es una displasia esquelética rara, de herencia autosómica dominante, que se caracteriza por la presencia de disostosis facial y periférica, talla baja y diferentes grados de obesidad. La acrodisostosis de tipo 1, secundaria a la mutación heterocigota en el gen PRKAR1A (17q24.2), se caracteriza por la asociación de resistencia hormonal múltiple con anomalías esqueléticas. Su incidencia está infradiagnosticada debido a que comparte rasgos clínicos y de laboratorio con otras entidades como el seudohipoparatiroidismo. Presentamos el caso de una niña de 8 años, con acrodisostosis tipo 1, confirmada mediante estudio genético. Además del fenotipo característico descrito, la talla baja y la resistencia hormonal, la paciente presentó una afectación progresiva de la función pulmonar: un patrón pulmonar obstructivo no reversible. En la literatura revisada, no se han encontrado otros casos que describan esta asociación entre acrodisostosis y afectación respiratoria.

Acrodysostosis is a rare skeletal displasia, of autosomal dominant inheritance, characterized by the presence of facial and peripheral dysostosis, short stature and obesity. Type 1 acrodysostosis is secondary to a mutation in the PRKAR1A (17q24.2) gene, which results in multi hormonal resistance and skeletal anomalities. This syndrome is under-diagnosed as it shares analytical and clinical characteristics with other entities, such as pseudohypoparathyroidism. We report the case of an eight-year-old girl with genetically confirmed type 1 acrodysostosis. In addition to the characteristic phenotype described, the short stature and the hormonal resistance, the patient suffered a progressive lung function deterioration: an irreversible pulmonary obstructive pattern. We have not found in previous literature cases reporting an association between acrodysostosis and lung function impairement.

A Case of Shwachman-Diamond Syndrome Confirmed with Genetic Analysis in a Korean Child

Shwachman-Diamond syndrome (SDS) is an autosomal recessive genetic disorder, consisting of exocrine pancreatic insufficiency, chronic neutropenia, neutrophil chemotaxis defects, metaphyseal dysostosis, short stature, dental caries, and multiple organ involvements. Although SDS is the second most common hereditary abnormality of exocrine pancreas following cystic fibrosis in the Western countries, it has rarely been reported in Asia. We diagnosed a case of SDS in a 42-month-old girl, and genetic analysis including the relatives of the patient confirmed the diagnosis for the first time in Korea. She had short stature, steatorrhea, dental caries, and recurrent prulent otitis media and pneumonias. Laboratory studies revealed cyclic neutropenia, and serum levels of trypsin, amylase, and lipase were decreased. Simple radiography revealed metaphyseal sclerotic changes at the distal femur. A CT scan demonstrated a fatty infiltration and atrophy of the pancreas. On direct sequencing analysis of Shwachman-Bodian-Diamond Syndrome gene exon 2 region, the patient was homozygous for the c.258+2T>C mutation and heterozygous for the c.183_184TA>CT mutation and c.201A>G single nucleotide polymorphism. Treatment with pancreatic enzyme replacement, multivitamin supplementation, and regular to high fat diet improved her weight gain and steatorrhea.