X-linked hypophosphatemic rickets without "rickets".
Wrist and knee radiographs from children with X-linked hypophosphatemic rickets were analyzed and compared with those from normal children and children with established rickets to assess whether radiographically apparent rickets is a consistent abnormality in X-linked hypophosphatemia. The absence or presence of rickets was correctly identified in 94.8% of wrist and knee films from normal and positive controls. In contrast, patients with X-linked hypophosphatemia exhibited rachitic abnormalities in only 5 of 11 wrist and 13 of 15 knee radiographs. As a result, 4 patients within this study group had rickets at the knee and not at the wrist, whereas 5 displayed classic defects at both sites. Perhaps more important, 2 patients, aged 3.8 and 5.2 years, displayed no evidence of rickets in either wrist or knee films, although relatives exhibited demonstrable rachitic abnormalities. Our data indicate that radiographically detectable rickets is a variable abnormality of X-linked hypophosphatemia and does not provide an unambiguous index for the diagnosis of this disease.
Econs
M J
MJ
Department of Medicine, Duke University Medical Center, Durham, NC 27710.
Feussner
J R
JR
Samsa
G P
GP
Effman
E L
EL
Vogler
J B
JB
Martinez
S
S
Friedman
N E
NE
Quarles
L D
LD
Drezner
M K
MK
D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005260:Female; D008040:Genetic Linkage; D006801:Humans; D007015:Hypophosphatemia, Familial / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000235:genetics; D007223:Infant; D007717:Knee / Q000000981:diagnostic imaging; D008297:Male; D015588:Observer Variation; D015995:Prevalence; D011859:Radiography; D012279:Rickets / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000235:genetics; D016037:Single-Blind Method; D014953:Wrist / Q000000981:diagnostic imaging; D014960:X Chromosome