[Clinical analysis and genetic diagnosis of short-limb inherited short stature diseases in children].

OBJECTIVE

To analyze the clinical manifestations, bone X-ray findings and genetic analysis results of three short-limb inherited short stature diseases: achondroplasia (ACH), hypochondroplasia (HCH) and pseudoachondroplasia (PSACH).

METHODS

The clinical manifestations, bone X-ray findings, and genetic analysis results of 10 children with genetically confirmed short-limb inherited short stature diseases, including 4 cases of ACH 3 cases of HCH, and 3 cases of PSACH, were analyzed.

RESULTS

The 10 patients had a mean body height of -3.69±1.79 SD, a mean sitting height/standing height ratio of 0.65±0.03, and a mean finger spacing/body height ratio of 0.93±0.04. Four ACH cases and 3 PSACH cases showed typical bone X-ray findings; one HCH case showed a smaller sciatic notch, and another HCH case showed no widening of interpedicular distance. G380R mutation in FGFR3 gene was detected in 3 of 4 ACH cases, and Y278C mutation in the other ACH case, N540K mutation in FGFR3 gene was detected in 3 HCH cases, and heterozygous mutations in COMP gene were detected in 3 PSACH cases.

CONCLUSIONS

Children with ACH and PSACH have severer short stature and skeletal deformities than children with HCH, who have mild, atypical clinical manifestations. Bone X-ray and genetic analysis are helpful for the diagnosis and differential diagnosis of the three diseases. The mutational hotspots in two genes are involved in the three diseases, which is conducive to clinical genetic diagnosis.