Murk Jansen's metaphyseal chondrodysplasia with long-term followup

Abstract

The fourteenth reported patient with Murk Jansen's metaphyseal chondrodysplasia is presented, with a remarkable followup from birth to the age of 15 years. Numerous invasive procedures were performed in pursuit of erroneous provisional diagnoses. Five of these patients presented in infancy with radiographic metaphyseal changes similar to rickets, but with preservation of the provisional zone of calcification. Following infancy, these patients reveal the more typical short-limbed dwarfism, with fusiform joints and bowed extremities.

Calcium metabolism in the jansen type of metaphyseal dysplasia

“…The early skeletal changes, hypercalcaemia and a tendency to hyperphosphataemia suggest hyperparathyroidism, but the parathyroid glands were normal on surgical exploration in three patients [5,7,19] and the pathogenesis of the mineral disturbance is still unknown. We studied the calcium metabolism in a hypercalcaemic girl with JMD from birth to the age of 3.5 years in order to elucidate the pathogenesis of the hypercalcaemia.…”

“…Elevated serum calcium concentrations have been noted in seven patients [2,5,6,7,9,14,19]. The early skeletal changes, hypercalcaemia and a tendency to hyperphosphataemia suggest hyperparathyroidism, but the parathyroid glands were normal on surgical exploration in three patients [5,7,19] and the pathogenesis of the mineral disturbance is still unknown.…”

Skull Base and Cervical Spine Involvement in Jansen Syndrome: Case Report

“…There is a steady increase in severity of bone changes in adults with prominence of supraorbital and zygomatic arches and underdevelopment of the paranasal sinuses, giving rise to a very distinctive facial profile [3,20] . Brachycephaly and dolichocephaly have been reported as well but in general, the bone involvement with sclerosis in JMD is limited to the skull base as compared to other dysplasias [12] .…”

“…The JMD gene has been localized to the 3p22-p21.1 chromosome, which is the parathyroid hormone-related peptide receptor ( PTHR1 ). Four distinct mutations in the PTHR1 gene have been recognized including His223Arg, Thr410Pro, Ile458Argw, and Thr410Arg [6,[18][19][20] . Genetic analysis and counseling can be of possible benefit for the affected individuals and their families as the treatment for this disorder has largely been symptomatic and supportive.…”

“…More than 20 cases of JMD had been reported in the literature but this could be inaccurate as there is considerable variability in the clinical and radiological findings, depending on the age of the patient, which may have led to misdiagnoses. Furthermore, not all published case reports have included complete radiological documentation, limiting our ability to properly analyze for JMD [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] .…”