Thumb duplication: molecular analysis of different clinical types

Area of Science:

• Genetics
• Molecular Biology
• Developmental Biology

Background:

• Thumb duplication, a congenital anomaly, presents in various forms.
• Polydactyly, often associated with genetic factors, requires molecular understanding for improved diagnostics.

Purpose of the Study:

• To conduct molecular analysis of thumb duplication.
• To identify novel gene mutations associated with Wassel types III and IV thumb duplication.

Main Methods:

• DNA extraction from preoperative blood samples of patients with polydactyly.
• Clinical Exome Solution and Next-Generation Sequencing (NGS) on the Illumina NextSeq-500 platform.
• Bioinformatics analysis using Sophia DDM® SaaS algorithms.

Main Results:

• Eight mutations were detected across six genes (CEP290, RPGRIP1, TMEM216, FBN1, CEP164, MEGF8), including four novel mutations.
• The patient with Wassel type III duplication had three mutated genes, while the Wassel type IV patient had five.
• Two mutated genes were common between the patients, but only one specific mutation was shared.

Conclusions:

• Newly identified mutations in genes associated with ciliopathies (which can include polydactyly) are likely linked to thumb duplication.
• These findings can assist in prenatal diagnosis and predicting surgical treatment strategies.
• The identified mutations may have future applications in gene therapy for related conditions.