Pycnodysostosis.

Abstract

The first Scottish family with pycnodysostosis is reported. The clinical and radiological findings in the two affected men are recorded. This rare sclerosing bone dystrophy was first described by Maroteaux and Lamy in 1962' as a variant of osteopetrosis (Albers-Schonberg disease). They suggested the eponymous title of 'maladie de Toulouse-Lautrec' who is thought to have been r it III b Li FIG 1 Family pedigree.

Osteomyelitis of the jaws in patients with pycnodysostosis: a systematic review

“…The osteoclasts of patients with PYCD are unable to degrade collagen I and other non-collagenous proteins that form the bone matrix, while these cells maintain their demineralizing activity, resulting in abnormal bone metabolism. 24 , 25 The absence of cathepsin K also seems to stimulate cortical bone formation through the negative control of periostin secreted by osteoblasts and osteocytes, a fact that explains the apparent contradictory effect of the increased bone density in PYCD, 26 , 27 demonstrated by the presence of osteosclerosis. The latter was observed in 11/26 patients.…”

“…The bone quality in patients with PYCD is low (fragile and poorly organized matrix). Bone strength is reduced due to acidification, increasing the risk of fractures, particularly in the lower extremities 1 , 27 ( Fig. 3 D).…”

“… 17 Our results were consistent with the literature, with the mandible being the most affected site (n = 22). 2 , 5 , 6 , 11 , 12 , 13 , 14 , 15 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 27 , 28 , 29 , 30 …”

Picnodisostosis familiar, reporte de un caso tras 10 años de seguimiento

“…Asimismo, no es común que se haga un desglose analítico del árbol genealógico de tales pacientes como en las publicaciones de Jáquez, Milles y Marrero-Riverón. 17,18,19 En esta serie de casos, llama la atención que existen dos uniones entre miembros de ambas familias (dos hermanos de la misma familia paterna con dos hermanas de la misma familia materna), sin que ninguno de los cuatro hijos de la primera unión presentase la afectación, mientras que por el otro lado, los tres hijos de la segunda unión heredaron el padecimiento. No se encuentran registros de un hecho similar en la bibliografía internacional.…”

Cathepsin K Mutation—A Subtle Clinical Presentation

“…Pyknodysostosis is an uncommon autosomal recessive disorder characterized by a defective cathepsin K gene. Cathepsin K is a cysteine protease lysosomal protein expressed in the osteoclasts encoded by chromosome 1q21 and is involved in the degradation of the matrix (type 1 collagen) of bone and cartilage [ 1 , 2 ].The estimated frequency of the disorder ranges from 1 to 1.7 per million. It was first described in 1962 [ 3 , 4 ].…”