染色体15q11-q13区域易发生细胞遗传学异常,该染色体区域的多种结构重排包括缺失、间质重复、移位、倒置和额外标记染色体,反复的结构重排与低拷贝数重复序列有关[1].研究显示,在发育迟缓和孤独症患者中染色体15q11-q13重复综合征的患病率分别约为1/600[2]和2/100[3].

Objective:To improve recognition of the clinical phenotype and genotype of achondroplasia(ACH).Methods:The clinical data and genetic test results of 2 children with ACH were analyzed retrospectively, and the related literature was reviewed.Results:Case 1 was a 1-year-old girl whose mother was short in stature.She was admitted to the hospital due to knee reflexes of both lower limbs for more than 9 months.Physical examination showed that her head circumference was 45 cm and she had short stature, short limbs, low muscle tension of both lower limbs, the developmental quotient was 65 scores.Bilateral ilium and hip joint lesions by X-ray were considered as ACH.According to the submitted gene results, FGFR3 gene c. 1138G >A (p.Gly380Arg) of the girl showed the heterozygous variation, and that gene of her mother showed the heterozygous variation.Case 2 was a 10-month-old girl, who was admitted to the hospital due to limb weakness for over 5 months.Physical examination showed head circumference of 46 cm, short stature, short limbs, reduced muscle tension of limbs, grade 4 muscle strength of limbs, and the developmental quotient was 41 scores.X-ray showed that both lower limbs were in accordance with ACH.The gene results suggested the heterozygous variation of FGFR3 gene c. 1138G >A (p.Gly380Arg) in the girl(a novel mutation), and a wild-type gene in her parents. Conclusions:The clinical features of achondroplasia are diverse.The bone changes and nerve development also need to be recognized and discriminated.