Achondroplasia (ACH) and Hypochondroplasia (HCH) are closely related disorders that reflect a spectrum of change with achondroplasia being the more severe (for fuller descriptions look under the individual tests listing). The classic features include rhizomelic shortening, megalocephaly, lumbar lordosis and other skeletal abnormalities.  Intelligence is unaffected. The symptoms for the two disorders can often overlap. Most cases are spontaneous; however, the remainder are inherited in an autosomal dominant manner.  In the inherited form, the disease is considered fully penetrant. Defects in the fibroblast growth factor receptor 3 (FGFR3) gene (chromosome 4p) have recently been discovered to cause greater than 99% of ACH and 60-70% of HCH of both spontaneous and hereditary types. In order to most efficiently and economically diagnose these patients the Dwarfism Panel combines the individual tests for ACH and HCH into a panel that can be ordered as a separate test.

• To confirm the nature of the dwarfism in an affected individual.
• To evaluate fetuses with unusually small stature by ultrasound for the possibility of spontaneous ACH or HCH.
• Individuals at risk who wish prenatal diagnosis.

• PCR amplification followed by DNA sequencing  or mutation specific restriction enzyme digestion.

• Blood EDTA (purple top) tubes:  

            Newborn: minimum 1-2 mL          

            Child/Adult: prefer 2 tubes of 3-5 mL

• Prenatal testing: Please contact the laboratory for instructions.

TURNAROUND TIME:     10 working days

CPT CODES: