Abstract
Purpose: :
To determine the possible genetic defect underlying congenital glaucoma (CG) in Italy, molecular analysis was performed on CYP1B1 and MYOC/TIGR genes.
Methods: :
Blood samples from 120 patients affected by CG including high intraocular pressure (IOP), epiphora, corneal oedema, photophobia, blepharospasm and ocular enlargement were collected to perform DNA extraction and sequence analysis.
Results: :
Seventeen different variations of CYP1B1 were found in 36 of the 120 CG patients. Twelve of these changes had been identified in previous papers as disease-causing mutations, while L26R, P52L, A106D, A237E and F440L are described here for the first time. The F440L has always been found in cis with the P52L, both in patients and in healthy carriers, suggesting its role as a rare polymorphism linked to the P52L; the other new found variations could possibly play a patogenetic role. G61E and 1775-1801dup27 are the most frequent mutations in our patients. Previously described CYP1B1 polymorphisms (R48G, A119S, L432V, D449D and N453S) were also analysed and a particular haplotype was identified in affected individuals with CYP1B1 mutations. The transcript region of the MYOC/TIGR gene was studied in all the patients bearing only one mutation in CYP1B1 gene, and two aminoacidic variations (A447V and R76K) were identified.
Conclusions: :
Our results confirm the major role of CYP1B1 gene in Italian patients affected by congenital glaucoma and also suggest an autosomic recessive role of MYOC/TIGR in a digenic inheritance model.
Keywords: genetics • intraocular pressure • mutations