Analysis of the genotype and phenotye in 3 pedigrees with Stargardt disease

Objective To analyze the relationship between genotype and phenotype in 3 pedigrees with Stargardt disease. Methods Three pedigrees with Stargardt disease were included in Ningxia Eye Hospital from January 2017 to September 2017.The clinical features of patients and other family members were evaluated by ophthalmic examinations, including visual acuity, best corrected visual acuity (BCVA), fundus examination, optical coherence tomography (OCT), fundus fluorescein angiography (FFA) and electroretinogram (ERG). The periphery blood sample of 5 ml from patients and 1 family member with normal phonotye in each family were collected.The next generation sequencing, PCR and direct sequencing were used to confirm the disease-causing mutation.The relationship between genotype and phenotype was analyzed.This study was approved by Ethic Committee of Ningxia Eye Hospital and informed consent was obtained from each subject. Results In 3 Stargardt pedigrees, 2 pedigrees showed autosomal recessive inheritance, and 1 pedigree was pseudodominant inheritance.Five mutations on ABCA4 gene were detected and p. F2188S and p. Y345C were novel muations.All pedigrees carried two heterozygous mutation.The onset age of the patients were adolescence except just one patient who suffered at the age of 50 years old.The visual acuity was severely affected and the OCT indicated different degrees of macular atrophy.The results of the ocular fundus photography and the FFA were variable. Conclusions The patients with stargardt disease often carry heterozygous mutation on ABCA4 gene and available characteristics, including early onset age, varying ocular fundus and severe visual impairment.Next generation sequencing technique shows the advantages of rapid and high efficiency in the diagnosis of Stargardt disease. Key words: Stargradt disease; Genotype; Phenotype; Pedigree