Division of Medical Genetics, Departments of Pediatrics and Genetics, Stanford University Medical Center, Stanford, California, USA.
Am J Med Genet A. 2012 Nov;158A(11):2911-6. doi: 10.1002/ajmg.a.35604. Epub 2012 Sep 14.
Cartilage-hair hypoplasia (CHH) is a rare recessive metaphyseal chondrodysplasia characterized by severe short stature, ectodermal dysplasia, anemia in childhood, immune deficiency, susceptibility to malignancy, and normal intelligence. Short, thick long bones, metaphyseal flaring and irregularities, and globular epiphyses at the knees and ankles are the typical radiographic findings. The diagnosis is primarily made on the basis of clinical features, although mutations in the RMRP gene have recently been described in affected individuals, facilitating confirmation of the clinical diagnosis in atypical patients. We present a patient with two RMRP mutations whose stature and ectodermal features supported the diagnosis of CHH, but whose radiographic findings and other extraskeletal findings did not. We propose that the most consistent and reliable features of CHH are short stature of prenatal onset and ectodermal dysplasia, and suggest that the diagnosis of CHH be considered and mutation analysis pursued even when typical radiographic findings are absent.
软骨毛发发育不全（CHH）是一种罕见的隐性干骺端软骨发育不良，其特征为严重的身材矮小、外胚层发育不良、儿童期贫血、免疫缺陷、易发生恶性肿瘤和智力正常。短而粗的长骨、干骺端增宽和不规则、膝关节和踝关节球状骨骺是典型的放射学表现。该诊断主要基于临床特征，尽管最近在受影响的个体中描述了 RMRP 基因突变，这有助于在非典型患者中确认临床诊断。我们介绍了一名患者，其存在两种 RMRP 突变，其身材矮小和外胚层特征支持 CHH 的诊断，但放射学表现和其他骨骼外表现则不支持。我们提出，CHH 最一致和可靠的特征是产前起病的身材矮小和外胚层发育不良，并建议即使没有典型的放射学发现，也应考虑 CHH 的诊断并进行突变分析。
