Genotypes and phenotypes of hereditary eye diseases associated with early-onset high myopia / 中华实验眼科杂志

Objective:To analyze the genotype of hereditary eye diseases with early-onset high myopia (eoHM) and its relationship with phenotype.Methods:The families with eoHM were collected in Ningxia Eye Hospital from January 2019 to June 2020.The medical records of the probands and their family members were inquired and recorded in detail, and the relevant ocular examinations were performed.Peripheral venous blood samples were collected from patients and their family members, and whole-genome DNA was extracted.Sequence capture sequencing technology was applied to screen for disease-causing gene mutations in probands.The detected suspected pathogenic variants were verified by Sanger sequencing and were analyzed by family cosegregation analysis.According to ACMG guidelines, the pathogenicity of novel variants was evaluated.The original literature about hereditary eye diseases with eoHM was searched to analyze the relationship between mutated genes and clinical phenotype.This study protocol adhered to the Declaration of Helsinki.All subjects or their guardians were informed of the purpose and procedure of the study and signed the informed consent form.The study protocol was approved by the Ethics Committee of the People's Hospital of Ningxia Hui Autonomous Region (No.2016018).Results:A total of 20 eoHM families were collected, among which pathogenic variants associated with inherited eye diseases were detected in 8 families.Of the 8 probands, two were diagnosed with familial exudative vitreoretinopathy, one with X-linked retinitis pigmentosa, one with congenital stationary nightblindness, one with Stickler syndrome, one with achromatopsia, one with Leber congenital amaurosis, and one with gyrate atrophy of the choroid and retina.The first diagnosis age of the 8 probands was 4-7 years old, and they were all diagnosed as high myopia, with a refractive status ≤-6.00 DS.Genetic tests showed that the 8 probands carried a heterozygous variant c. 313A>G (p.M105Val) in FZD4 gene, a heterozygous variant c. 14_15insAAGA (p.Asp5fs *) in TSPAN12 gene, a heterozygous frameshift variant c. 2234_2237del (p.Arg745fs) in RPGR gene, a compound heterozygous variant of c. 481C>T (p.Gln161Ter *) and c. 355>T (p.Arg119Cys *) in GPR179 gene, a frameshift variant c. 1659_1660insACGGTGACCCTGGCCGTCCTGG (p.Pro554fs *) in COL2A1 gene, a compound heterozygous variant of c. 1811C>T (p.Thr604Ile *) and c. 967G>A (p.Gly323Ser) in PDE6B gene, a compound heterozygous variant of c. 604_619delTCCACGGCACTCAGGG (p.Ser202fs *) and c. 995G>C (p.Arg332Pro) in GUCY2D gene, a homozygous variant c. 772C>T (p.Pro241Leu) in OAT gene.Seven of them were novel variants.Compared with the previous literature, the clinical and gene phenotypes of the 8 families were analyzed in detail in this study, which provided the basis for the diagnosis of hereditary eye diseases with eoHM. Conclusions:EoHM is closely related to some hereditary eye diseases, which may be the reason for the early diagnosis of children and an important clue for clinicians to detect potential hereditary eye diseases.Further clinical evaluations of ocular structure and function as well as genetic screening in children with eoHM are recommended.

Cone-rod dystrophy associated with novel variations on CDHR1 and C2orf71 gene / 中华眼底病杂志

Objective:To observe and analyze the gene mutation and clinical phenotype of patients with cone and rod dystrophy (CORD).Methods:A pedigree investigarion. Two CORD pedigrees including 2 patients and 6 family members were enrolled in Ningxia Eye Hospital of People' Hospital of Ningxia Hui Automous Region for this study. The patients were from 2 unrelated families, all of whom were probands. Take medical history with best-corrected visual acuity (BCVA), color vision, slit lamp microscopy, indirect ophthalmoscopy, fundus color photography, optical coherence tomography (OCT), autofluorescence (AF), fluorescein fundus angiography (FFA), electroretinogram (ERG). The peripheral venous blood of patients and their parents was collected, whole genome DNA was extracted, Trio whole genome exome sequencing was performed, Sanger verification and pedigree co-segregation were performed for suspected pathogenic mutation sites. According to the law of inheritance, family history was analyzed to establish its genetic type. Mutational loci pathogenicity was analyzed according to the American College of Medical Genetics (ACMG) guidelines and 4 online tools.Results:Two CORD families showed autosomal recessive inheritance. The proband of pedigree 1 was female, 49 years old. Binocular vision loss with photophobia lasted for 9 years and night blindness for 4 years. The BCVA of right eye and left eye were 0.03 and 0.06, respectively. The results of ERG showed that the amplitudes of dark adaptation 0.01 b-wave and dark adaptation 3.0 a-wave and b-wave in both eyes were slightly decreased, and the amplitudes of light adaptation 3.0 a-wave and b-wave were severely decreased. The proband of pedigree 2 was male, 30 years old. Vision loss in both eyes for 4 years. Denying a history of night blindness. The BCVA of right eye and left eye were 0.3 and 0.2, respectively. The results of ERG showed that the amplitudes of dark adaptation 0.01 b-wave and dark adaptation 3.0 a-wave and b-wave in both eyes were slightly decreased, and the amplitudes of light adaptation 3.0 a-wave and b-wave were severely decreased. The color of optic disc in both eyes was light red, the macular area was atrophic, the foveal reflection disappeared, and the peripheral retina was punctate pigmentation. The main fundus changes in 2 patients were macular atrophy. The proband of pedigree 1 carried compound heterozygous variations c.439-2A>G (M1) and c.676delT (p.F226fs) (M2) on CDHR1 gene. Her father and mother carried M2 and M1 heterozygous mutations, respectively. The proband of pedigree 2 carried compound heterozygous variations c.2665dupC (p.L889fs) (M3) and c.878T>C (p.L293P) (M4) on C2orf71 gene. His father and mother carried M4 and M3 heterozygous mutations, respectively. According to ACMG guidelines and on line tools, 4 variations were considered as pathogenic level. Conclusions:M1 and M2 of CDHR1 gene and M3 and M4 of C2orf71 gene are new pathogenic mutations of CORD. All patients presented with the clinical phenotype of decreased visual acuity and macular atrophy.

Progress in the research on clinical features of Bestrophinopathies and mutations in BEST1 gene / 中华实验眼科杂志

Bestrophinopathies are a group of inherited macular dystrophies caused by BEST1 gene mutations including Best vitelliform macular dystrophy, adult-onset vitelliform macular dystrophy, autosomal dominant vitreoretinochoroidopathy and autosomal recessive bestrophinopathy.The main pathological mechanism of bestrophinopathies is that the primary lesion located in the retinal pigment epithelium will affect the photoreceptor cells.The mutations in BEST1 gene not only result in macular lesions, but also potentially affect the development of eyeball, and even cause serious complications such as angle-closure glaucoma and choroidal neovascularization.It is highly heritable and clinically heterogeneous.The same pathogenic mutation site in BEST1 can lead to different clinical phenotypes, which are complex and varied and can bring great confusion to clinicians, causing misdiagnosis and missed diagnosis the disease.This review aimed to summarize and analyze the clinical manifestations of bestrophinopathies and the research progress in BEST1 gene mutations, so as to improve the understanding of clinicians toward this kind of disease and provide reference for clinical practice and future research.

Genotypes and clinical phenotypes of Hermansky-Pudlak syndrome / 中华实验眼科杂志

Objective:To analyze the genotypes and clinical phenotypes of two families with Hermansky-Pudlak syndrome (HPS).Methods:The method of pedigree investigation was adopted.A Han Chinese HPS family and a Hui Chinese HPS family were enrolled in People's Hospital of Ningxia Hui Autonomous Region from June 2020 to May 2021.Clinical data of two probands and their phenotypically normal parents were collected.Relevant ocular and systemic examinations were carried out.Platelet dense granules in the two probands were observed with an electron microscope.DNA was extracted from peripheral venous blood collected from the subjects.The pathogenic genes were screened by whole exome sequencing.The potential disease-causing variations were analyzed by bioinformatics analysis.Validation and family cosegregation analysis of the pathogenic variations were performed by Sanger sequencing.The relationship between HPS-related gene variations and clinical characteristics was explored.This study adhered to the Declaration of Helsinki.The study protocol was approved by the Ethics Committee of Ningxia Eye Hospital, People's Hospital of Ningxia Hui Autonomous Region (No.2016018).Written informed consent was obtained from each subject or custodian before any medical examination.Results:The two families were consistent with autosomal recessive inheritance pattern.In family 1 with a family history of consanguineous marriage, the proband had no obvious hypopigmentation on his facial skin, hair, eyebrows and eyelashes.Horizontal nystagmus, exotropia, mild visual impairment, iris atrophy, positive light transmission, orange fundus, pigment loss, macular hypoplasia, prolonged prothrombin time in laboratory examination, and a significant reduction of platelet dense granules by electron microscopy were observed.The proband in family 2 had pale brown hair and eyebrows, severe visual impairment, normal iris pigment, longer thrombin time in laboratory tests, and characteristics similar to those of the proband in family 1.A novel homozygous variant c. 2887G>T (p.E963X) was detected in the HPS3 gene of the proband in family 1.The parents of the proband from family 1 both carried a heterozygous variant c.2887G>T (p.E963X).Compound heterozygous variants were detected in HPS5 gene of the proband in family 2, c.2952-2A>C splicing variation and heterozygous deletion (a 3 144-bp deletion, located in chr11: 18302108-18305251, exon 22).The parents of the proband from family 2 carried a heterozygous variation.The three novel variations were labeled as pathogenic according to the ACMG standards and guidelines. Conclusions:Family 1 is with HPS-3 and family 2 is with HPS-5.There is a certain genotype-phenotype correspondence in the two types of HPS.