Whole-exome sequencing analysis in a case of primary congenital glaucoma due to the partial uniparental isodisomy

Abstract

We described a clinical, laboratory, and genetic presentation of a pathogenic variant of the CYP1B1 gene through a report of a case of primary congenital glaucoma and a trio analysis of this candidate variant in the family with the sanger sequencing method and eventually completed our study with the secondary/incidental findings. This study reports a rare case of primary congenital glaucoma, an 8-year-old female child with a negative family history of glaucoma and uncontrolled intraocular pressure. This case's whole-exome sequencing data analysis presents a homozygous pathogenic single nucleotide variant in the CYP1B1 gene (NM 000104:exon3:c.G1103A:p.R368H). At the same time, this pathogenic variant was obtained as a heterozygous state in her unaffected father but not her mother. The diagnosis was made based on molecular findings of whole-exome sequencing data analysis. Therefore, the clinical reports and bioinformatics findings supported the relation between the candidate pathogenic variant and the disease. However, it should not be forgotten that primary congenital glaucoma is not peculiar to the CYP1B1 gene. Since the chance of developing autosomal recessive disorders with low allele frequency and unrelated parents is extraordinary in offspring. However, further data analysis of whole-exome sequencing and sanger sequencing method were applied to obtain the type of mutation and how it was carried to the offspring.

Keywords: CYP1B1; glaucoma; primary congenital; sequence analysis; whole-exome sequencing.

Fig. 1.

Trio data analysis of the sanger sequencing method in the family. (A) Proband: homozygous state of variation (A/A). (B) Father: heterozygous state of variation G1103>A (G/A). (C) Mother: homozygous state of wildtype (A/A).

Fig. 2.

Probable range of uniparental isodisomy in the case observed by Integrative Genomics Viewer (IGV) and the Sanger sequencing method. At intervals of RMDN2: NM_144713:exon2:c.G776A:p.G259D (rs4670800) and CYP1B1: NM_000104:exon3:c.G1103A:p.R368H (rs79204362).