GeneDx :: Tests :: Hypophosphatemic rickets (autosomal dominant form), Hypophosphatemic rickets (X-linked form), Pseudo-vitamin D deficiency rickets (autosomal recessive)

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Hypophosphatemic rickets (autosomal dominant form)
Hypophosphatemic rickets (X-linked form)
Pseudo-vitamin D deficiency rickets (autosomal recessive)

FGF23 (in dominant rickets)
PHEX (in X-linked rickets)
CYP27B1 (in recessive rickets)

Inherited rickets is often associated with growth retardation, bowing of the lower extremities, and poor dental development. X-linked dominant hypophosphatemic rickets, due to mutations in the PHEX gene, is the most common inherited form of the disorder. Both males and females are affected with the disease and male-to-male transmission is NOT observed. Few cases of dominant hyophosphatemic rickets are associated with mutation in the autosomal FGF23 gene. Rickets due to mutation in FGF23 demonstrates greater clinical variability due to incomplete penetrance and delayed onset. Male-to-male transmission of FGF23 mutation is possible. Rickets due to both PHEX and FGF23 is NOT responsive to treatment with Vitamin D. Pseudovitamin D-deficiency rickets is an autosomal recessive condition due to mutations in the CYP27B1 gene and is responsive to treatment with Vitamin D. Choosing which gene to analyze in a patient with inherited rickets should be based on family and/or medical history. For sporadic cases, analysis of PHEX should precede that of FGF23, as it is the most common cause of Vitamin D-resistant rickets.

Mutations in each of the three genes associated with hereditary rickets are identified by complete sequence analysis of entire coding region of the associated genes. The analysis is performed on genomic DNA from venous blood (1-5ml in EDTA) or buccal swabs (GeneDx kits only). Carrier detection in relatives and prenatal diagnosis is available once the mutation in a family has been defined.

Information Sheet (FGF23)
Information Sheet (PHEX)
Information Sheet (CYP27B1)
Consent Document (FGF23)
Consent Document (PHEX)
Consent Document (CYP27B1)
Genetic Test Sample Submission Form (Test Requisition Form) including Payment Options

Rickets, hypophosphatemic, Vitamin D-resistant, pseudovitamin D-deficiency, osteomalacia, leg bowing, fibroblast growth factor, FGF23, FGF 23

Hypophosphatemic rickets (autosomal dominant form) Hypophosphatemic rickets (X-linked form) Pseudo-vitamin D deficiency rickets (autosomal recessive)

Hypophosphatemic rickets (autosomal dominant form)
Hypophosphatemic rickets (X-linked form)
Pseudo-vitamin D deficiency rickets (autosomal recessive)