Desbuquois dysplasia type 1 (DBQD1) is a very rare skeletal dysplasia characterized by growth retardation, short stature, distinct hand features, and a characteristic radiological monkey wrench appearance at the proximal femur. We report on 2unrelated Egyptian patients having the characteristic features of DBQD1 with different expressivity. Patient 1 presented at the age of 45 days with respiratory distress, short limbs, faltering growth, and distinctive facies while patient 2 presented at 5 years of age with short stature and hypospadias. The 2 patients shared radiological features suggestive of DBQD1. Whole-exome sequencing revealed a homozygous frameshift mutation in the CANT1 gene (NM_001159772.1:c.277_278delCT; p.Leu93ValfsTer89) in patient 1 and a homozygous missense mutation (NM_138793.4:c.898C#x3e;T; p.Arg300Cys) in patient 2. Phenotypic variability and variable expressivity of DBQD was evident in our patients. Hypoplastic scrotum and hypospadias were additional unreported associated findings, thus expanding the phenotypic spectrum of the disorder. We reviewed the main features of skeletal dysplasias exhibiting similar radiological manifestations for differential diagnosis. We suggest that the variable severity in both patients could be due to the nature of the CANT1 gene mutations which necessitates the molecular study of more cases for phenotype-genotype correlations.
Mol Syndromol

中文翻译：

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两名因纯合 CANT1 突变导致 Desbuquois 发育不良的埃及患者的首次报告

Desbuquois 发育不良 1 型 (DBQD1) 是一种非常罕见的骨骼发育不良，其特征是生长迟缓、身材矮小、手部特征明显，以及股骨近端的特征性放射学猴子扳手外观。我们报告了 2 名具有不同表达性的 DBQD1 特征的无关埃及患者。患者 1 在 45 天时出现呼吸窘迫、四肢短小、生长迟缓和独特的面容，而患者 2 在 5 岁时出现身材矮小和尿道下裂。这 2 名患者具有提示 DBQD1 的放射学特征。全外显子组测序揭示了CANT1中的纯合移码突变患者 1 中的基因 (NM_001159772.1:c.277_278delCT; p.Leu93ValfsTer89) 和患者 2 中的纯合错义突变 (NM_138793.4:c.898C#x3e;T; p.Arg300Cys)。DBQD 的表型变异性和可变表达性在我们的患者中很明显。阴囊发育不全和尿道下裂是另外未报告的相关发现，从而扩大了该疾病的表型谱。我们回顾了表现出相似放射学表现的骨骼发育不良的主要特征，以进行鉴别诊断。我们认为，这两名患者的严重程度不同可能是由于CANT1基因突变的性质，这需要对更多病例的表型-基因型相关性进行分子研究。
摩尔综合症