Ectopic calcification among families in the Azores: clinical and radiologic manifestations in families with diffuse idiopathic skeletal hyperostosis and chondrocalcinosis.
OBJECTIVE
Twelve families that were multiply affected with diffuse idiopathic skeletal hyperostosis (DISH) and/or chondrocalcinosis, were identified on the island of Terceira, The Azores, potentially supporting the hypothesis that the 2 disorders share common etiopathogenic factors. The present study was undertaken to investigate this hypothesis.


METHODS
One hundred three individuals from 12 unrelated families were assessed. Probands were identified from patients attending the Rheumatic Diseases Clinic, Hospital de Santo Espírito, in The Azores. Family members were assessed by rheumatologists and radiologists. Radiographs of all family members were obtained, including radiographs of the dorsolumbar spine, pelvis, knees, elbows, and wrists, and all cases were screened for known features of chondrocalcinosis.


RESULTS
Ectopic calcifications were identified in 70 patients. The most frequent symptoms or findings were as follows: axial pain, elbow, knee and metacarpophalangeal (MCP) joint pain, swelling, and/or deformity, and radiographic enthesopathic changes. Elbow and MCP joint periarticular calcifications were observed in 35 and 5 patients, respectively, and chondrocalcinosis was identified in 12 patients. Fifteen patients had sacroiliac disease (ankylosis or sclerosis) on computed tomography scans. Fifty-two patients could be classified as having definite (17%), probable (26%), or possible (31%) DISH. Concomitant DISH and chondrocalcinosis was diagnosed in 12 patients. Pyrophosphate crystals were identified from knee effusions in 13 patients. The pattern of disease transmission was compatible with an autosomal-dominant monogenic disease. The mean age at which symptoms developed was 38 years.


CONCLUSIONS
These families may represent a familial type of pyrophosphate arthropathy with a phenotype that includes peripheral and axial enthesopathic calcifications. The concurrence of DISH and chondrocalcinosis suggests a shared pathogenic mechanism in the 2 conditions.
Bruges-Armas
Jácome
J
Hospital de Santo Espírito, Azores, Portugal, and University of Oxford, UK. jacome.armas@netc.pt
Couto
Ana Rita
AR
Timms
Andrew
A
Santos
Margarida R
MR
Bettencourt
Bruno Filipe
BF
Peixoto
Maria José
MJ
Colquhoun
Katherine
K
McNally
Eugene G
EG
Carneiro
Victor
V
Herrero-Beaumont
Gabriel
G
Brown
Matthew A
MA
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001394:Azores; D002805:Chondrocalcinosis / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000235:genetics; D005260:Female; D006801:Humans; D004057:Hyperostosis, Diffuse Idiopathic Skeletal / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000235:genetics; D008297:Male; D008875:Middle Aged; D010375:Pedigree; D011859:Radiography