Objective To observe and analyze the gene mutation and clinical phenotype of patients with cone and rod dystrophy (CORD). MethodsA 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. ResultsTwo 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. ConclusionsM1 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.
ObjectiveThe clinical phenotypes and pathogenicity of isolated cone-rod dystrophy (CORD) caused by two novel complex heterozygous variants of the CEP290 gene were analyzed using high-resolution multi-mode imaging and gene detection techniques. MethodsA retrospective study. Two patients and two family members from a CORD family who were diagnosed by genetic testing at Henan Provincial People's Hospital in December 2021 were included in the study. All subjects underwent best-corrected visual acuity (BCVA), color fundus photography, autofluorescence, swept-source optical coherence tomography (SS-OCT), adaptive optics fundus imaging, static threshold field, full field and multiple electroretinogram (ERG) examination, as well as other systemic examinations throughout the body. The peripheral venous blood of the subjects was collected, and the whole genome DNA was extracted. DNA sequencing was performed using the Inherited Retinal Disease Kit PS400, and Sanger verification and pedigree co-segregation analysis were performed on the suspected pathogenic mutation sites. Validation was performed by Sanger sequencing, pathogenicity analysis was performed in accordance with the American College of Medical Genetics and Genomics (ACMG) guidelines. Conservation of variation among different species was analyzed by GERP++, Clustal Omega and Weblogo. ResultsBoth patients were male, and their ages were 21 and 29 years old, respectively. The right eye and left eye about BCVAs were 0.7, 0.4 and 0.3, 0.4, respectively. The full field and multiple electroretinogram ERG showed a decreased function of cones and rods, especially cones. SS-OCT showed thinning of the outer nuclear layer of macular, and attenuation of ellipsoid zone reflectivity in B-scan. Adaptive optics fundus imaging examination showed that the arrangement of cone cells in the fovea of the fovea was disordered and the density decreased, and the retinal pigment epithelial cells were seen through the atrophy of cone cells in some areas at 10°visual angle. No obvious abnormality was found in other systemic examinations of the whole body. Genetic testing showed that 2 novel compound heterozygous variants c.950T >A (p.Leu317*) (M1) and c.4144_4149del (p.Tyr1382_Glu1383del) (M2) in CEP290 were found in two patients. The first variant was predicted to be harmful in MutationTaster and CADD. GERP++ showed highly conserved among different species. The pathogenicity of the variant was suspected to be likely pathogenic according to ACMG guidelines. The pathogenicity of the second variant was uncertain significance. The parents of the proband had no similar ocular abnormalities. Verified by Sanger sequencing, it was consistent with co-separation in the family. ConclusionsPatients with pure CORD caused by CEP290 gene mutation still retain better vision when the cone structure is abnormal, the density is decreased, and the function of cone and rod cells is decreased. CEP290 M1 and M2 are newly discovered nonsense mutations and newly discovered deletion mutations, which expanded the causative gene spectrum of pure CORD.
Objective To observe and analyze the ocular clinical features and pathogenic genes of Alström syndrome (ALMS). MethodsA retrospective clinical study. From October 2020 to July 2022, 3 patients and 5 normal family members from 2 families affected with ALMS who visited in the Ophthalmology Department of Henan Children's Hospital were enrolled in the study. These 2 families were without blood relationship. The medical history and family history were inquired. Best corrected visual acuity (BCVA), fundus color photography, full-field electroretinogram (ERG), frequency domain optical coherence tomography (OCT) and systemic examination were performed. 3 ml peripheral venous blood of patients and their family members were collected, and the whole genomic DNA was extracted. The second generation sequencing analysis was performed on these members. The suspected pathogenic mutation sites were verified by Sanger, and the pathogenicity of the gene mutation sites were determined by bioinformatics analysis. ResultsThree patients from two families all developed nystagmus and photophobia in infancy. In the family 1, the BCVA of both eyes of the proband was no light perception. The fundus examination revealed vascular attenuation and retinal pigment abnormality. OCT showed retinal thinning, loss of photoreceptor layer and atrophy of the retinal pigment epithelium layer. ERG examination showed extinguished. The BCVA of the proband’s younger brother was 0.04 in the right eye and 0.02 in the left eye. The fundus examination revealed vascular attenuation but the pigment distribution was roughly normal. OCT showed blurred photoreceptor layers in both eyes. ERG examination showed extinguished. Two patients developed sensorineural deafness, obesity, acanthosis nigricans, insulin resistance/diabetes, and abnormal liver function. In addition, the proband also had left heart enlargement, hyperlipidemia and abnormal kidney function. The results of genetic testing showed that the proband and his younger brother had compound heterozygous mutations in exon 8 (c.1894C＞T/p.Gln632*, M1) and exon 10 (c.9148_9149delCT/p.Leu 3050 Leufs*9, M2) of ALMS1, which were both known mutations. The father of the proband was a carrier of M1 and the mother of the proband was a carrier of M2. The proband of the family 2 had a normal fundus at 23 months old. The amplitude of ERG b wave under the stimulation of the dark adaptation 0.01 and a, b wave under the stimulation of dark adaptation 0.3 were all mild reduced. The amplitude of ERG a, b wave under the stimulation of the light adaptation 0.3 was severity decreased. At 4 years old, the BCVA was 0.01 in the right eye and 0.05 in the left eye. The fundus examination revealed vascular attenuation and bilateral blunted foveal reflex. In addition to severely diminished of a, b wave under the stimulation of dark adaptation 0.3, the rest showed extinguished. There were no systemic abnormalities. The results of genetic testing showed that the proband had compound heterozygous mutations in exon 11 (c.9627delT/p.Pro3210Glnfs*22, M3) and exon 5 (c.1089delT/p.Asp364Ilefs*13, M4) of ALMS1, which were both novel mutations. The father of the proband was a carrier of M3 and the mother of the proband was a carrier of M4. ConclusionsNystagmus and photophobia are often the first clinical manifestations of ALMS. In the early stage, the fundus can be basically normal. As the disease progresses, the fundus examination reveals vascular attenuation and retinal pigment abnormality, and the reflection of the fovea is unclear. OCT shows the photoreceptor cell layers are blurred or even lost. The final ERG is extinguished. M1, M2, and M3, M4 compound heterozygous mutations may be the pathogeny for family 1 and family 2, respectively.
Objective To observe the clinical phenotype of patients with CACNA1F gene variant. MethodsA retrospective clinical study. From January 1, 2022 to October 1, 2023, 36 patients with CACNA1F gene mutation-related eye diseases diagnosed by clinical examination and genetic testing in Changsha Aier Eye Hospital and Jinan Purui Eye Hospital were included in the study. All patients underwent best-corrected visual acuity (BCVA), medical optometry, fundus color photography, optical coherence tomography, full-field electroretinography (ERG), nystagmus examination, and genetic whole-exon sequencing. BCVA was performed using log visual acuity charts and converted to (logMAR). The nystagmus examination was performed using a helmet-mounted multifunctional video eye movement recording system. The clinical phenotypic characteristics were observed. Results At total of 36 patients were male, aged was (6.69±5.26) years. There were 36 cases of myopia (38.89%, 14/36), and the spherical equivalent was (−3.01±4.84) D. There were 14 different genetic variants including 7 cases of pathogenic variants, 20 cases of suspected pathogenic variants and 9 cases of unknown pathogenic variants, respectively. logMAR BCVA was 0.67±0.27; 26 patients had optic nerve atrophy (72.22%, 26/36); 6 had optical nerve hypoplasia (16.67%, 6/36). Fundus pigment dysplasia with mild iris transillumination was found in 4 cases (11.11%, 4/36). There were 5 cases of foveal dysplasia (Thomas grade) 1 (13.89%, 5/36). In full-field ERG examination, the B-wave reduction of the maximum mixed reaction of dark adaptation showed a negative waveform, and the amplitude of the shock potential was seriously reduced. The main phenotypes were residual type (residual dark adaptation 0.01 reaction wave and bright adaptation 3.0 reaction wave, and the response decreased at 30 Hz to a double-peak wide wave), dominant type of bright adaptation decreased (all light adaptation extinguished, all dark adaptation extinguished), and total extinction type (all light adaptation extinguished). Among them, 10 cases presented with residual ERG (27.78%, 10/36), 8 cases with photopic reduced ERG (22.22%, 8/36) and 18 with extinguished ERG (50.00%, 18/36). Low amplitude and high frequency pendulum (PLAHF) nystagmus waverforms were found in 32 cases (88.89%, 32/36), head oscillation in 27 cases (75.00%, 27/36) and chin up abnormal head posture in 26 cases (72.22%, 26/36), respectively. ConclusionsCACNA1F Gene variant eye diseases had diverse clinical phenotype. Clinical phenotype of PLAHF nystagmus is closely related with CACNA1F gene variant eye disease.