ObjectiveTo analyze the pathogenic gene types and phenotypic characteristics of 6 albinism families. Methods A retrospective series of case studies. Six probands of albinism and 20 family members were recruited for this study, 5 probands with clinical manifestations of oculocutaneous albinism (OCA) and 1 proband of ocular albinism (OA). Genomic DNA was extracted from peripheral venous blood which was collected from 6 probands and 20 family members. Genetic variations were screened by whole-exome sequencing or Sanger sequencing and then analyzed the relationship between genotypes and phenotypes. Results Genetic sequencing identified 6 potential pathogenic variants in 4 probands, including 2 compound heterozygous mutations in the 2 genes [TYR (c.1037-7T＞A, c.925_c.926insC), OCA2 (c.2359G＞A, c.587T＞C)] associated with OCA1 and OCA2, and 2 hemizygous mutations in the GPR143[GPR143 (c.11C＞G), GPR143 (c.333G＞A)] associated with OA1, respectively. In which, 5 were novel mutations and confirmed by Sanger sequencing. One case was accorded with OCA in clinical phenotype, but genetic diagnosis was OA1, the others were agreement between clinical diagnosis and genetic diagnosis. Conclusion There are 4 families with mutations in 6 families, representative of 3 type of albinism (OCA1, OCA2, OA1).
ObjectiveTo identify the causative genes of the posterior microphthalmia-retinal pigment degeneration family. MethodsA retrospective clinical study. One child (proband) and 3 family members of a family with posterior microphthalmia-retinitis pigmentosa diagnosed by clinical and genetic examination at Henan Provincial People's Hospital in July 2019 were included in the study. Medical history and family history, and draw pedigree of the patients was collected. Visual acuity, visual field, fundus color photography, optical coherence tomography and electroretinogram (ERG) were examined. The peripheral venous blood of the proband, his parents and sister, and extract the whole genome DNA was collected. Whole-exome sequencing was used to detect genetic variations, the suspected pathogenic variations were verified by Sanger sequencing, and the pathogenicity was determined by bioinformatics analysis. ResultsThe parents discovered the proband was poor vision at the age of 10 months. At the age of 3, the best corrected visual acuity of the right eye and the left eye were 0.3 and 0.4, respectively. No abnormality was found in anterior segment. Extremely high hyperopia in both eyes. The axial length was 14.47 mm and 15.78 mm, respectively. The optic disc of both eyes was relatively small and flushed, retinal folds can be observed in macular area, and no obvious pigment deposition was found. ERG examination showed that the rod system response and the maximal combined response of both eyes decreased slightly to moderately, and the single-flash cone response and the 30 Hz flicker response decreased moderately to severely. Genetic analysis revealed two novel mutations in the membrane frizzled-related protein (MFRP) gene in the proband: c.363delC/p.Thr121Thrfs*16, c.1627C＞T/p .Gln543Stop,37 in exon 4 and 13, the former was a frameshift mutation, encoding 16 amino acids and then terminated, and the latter was an nonsense mutation, truncated 37 amino acids, both which were predicted to be pathogenic and segregate with disease. The mother and sister carried c.363delC, and the father carried c.1627C＞T. ConclusionMFRP gene c.363delC/p.Thr121Thrfs*16, c.1627C＞T/p.Gln543Stop, 37 compound heterozygous mutation may be the pathogenic gene of this family.
ObjectiveTo identify the causative gene and observe the phenotypic characteristics of a family with isolated microphthalmia-anophthalmia-coloboma (MAC). MethodsA retrospective clinical study. One patient (proband) and 3 family members of a family with MAC visited the Henan Eye Hospital from May 2019 to May 2022 were included in the study. The patient's medical history and family history were inquired in detail, and the best corrected visual acuity (BCVA), slit lamp microscope, fundus photography, optical coherence tomography (OCT), ophthalmological B mode ultrasound and axial length (AL) measurement were performed. The peripheral venous blood of the proband, his parents and brother was collected for Trio whole-exome sequencing and pathogenic gene screening. Fluorescence quantitative Polymerase chain reaction was used to verify the suspicious variations. The clinical features of the patient's ocular and systemic also were observed. ResultsThe proband, male, was 3 years old at the first visit. The horizontal pendular nystagmus was detected in both eyes. Vertical elliptical microcornea and keyhole-shaped iris colobomas were detected in both eyes. The objective refraction at first visit (3 years old) was －4.00 DS/－0.50 DC×105° (OD) and －3.50 DS/－1.25 DC×80° (OS). Refraction and BCVA at 6 years old: －6.50 DS/－2.00 DC×110°→0.05 (OD) and －6.00 DS/－1.50 DC×80°→0.2 (OS). The AL at 4 years and 10 months old was 24.62 mm (OD) and 23.92 mm (OS), respectively. The AL at 5 years and 7 months old was 25.24 mm (OD) and 24.36 mm (OS), respectively. Ultrasonography shows tissue defects in both eyes. Fundus photography showed the inferior choroidal coloboma involving optic disc. OCT showed the optic disc in both eyes was abnormal with colobomas around, and the retinal neurosensory layer in colobomas area was disordered and thin; the retinoschisis was visible in the left eye. The proband's parents and siblings have normal phenotypes. Whole exome sequencing reveals a denovo heterozygous deletion of YAP1 gene: YAP1, chr11: 10280247-102100671, NM_ 001130145, loss 1 (EXON: 6-9). The results of bioinformatics analysis were pathogenic variants. Parents and siblings were of the wild type. ConclusionsLoss of heterozygosity in exons 6-9 of YAP1 gene is the pathogenic variation in this family. It can cause abnormal development of anterior segment, chorioretinal colobomas, deepening of axial myopia, even severe macular colobomas and retinoschisis.