Preliminary report on screening IGSF3 gene mutation in families with congenital absence of lacrimal puncta and canaliculi

AIM:To investigate the variation of IGSF3 gene in three families with congenital absence of lacrimal puncta and canaliculi,and to lay a foundation for further research on the pathogenic gene of congenital lacrimal duct agenesis.METHODS:The members of the three families were recruited.The ophthalmologic examinations in details,including slit-lamp biomicroscope,intraocular pressure and fundus examination,etc.were carried out.All patients were checked with paracentesis of puncta membrane and lacrimal duct probing,as well as the computed tomographydacryocystography(CT-DCG).Peripheral blood of 14 participants(3 normal)from three families were collected,4 mL each,for genomic DNA extraction,and 11 exon fragments of IGSF3 gene were amplified and sequenced by polymerase chain reaction(PCR)to determine whether there were IGSF3 genetic variation.RESULTS:A total of 14 members from three families were screened for 4 synonymous variants:c.930 C>T(p.Pro366=),c.1359 T>C(p.Ser709=),c.1797 G>A(p.Ser855=),c.1539 G>A(p.Ser769=),and 6 missense variants:c.l507 G>A(p.Gly759 Ser),c.1783 T>C(p.Trp851 Arg),c.1952 G>T(p.Ser 907 lle),c.3120 C>G(p.Asp1040 Glu),c.3123 C>G(p.Asp1041 Glu),c.3139_3140 insGAC(p.Asp1046_Pro1047 insAsp),and the latter three were only found in two patients with absence of lacrimal puncta and canaliculi combined with congenital osseous nasolacrimal canal obstruction from the first family.CONCLUSION:The same IGSF3 gene mutation c.31393140 insGAC is found in the patients with congenital absence of lacrimal puncta and canaliculi combine with osseous nasolacrimal canal obstruction.