Novel mutations in patients with X-linked Alport syndrome: Two case reports

A genotype-phenotype correlation is known to be associated with Alport syndrome (AS). Identifying novel mutations can expand the knowledge about the natural course of AS.

The first patient was a-15-year-old boy detected with proteinuria during the school health check-up. The second case was a-29-year-old woman, who visited the outpatient clinic for edema.

We performed targeted next-generation sequencing to identify the mutations associated with AS. Results were confirmed by Sanger sequencing and multiplex ligation-dependent probe amplification. Missense mutation (c.2332G>C, p.Gly778Arg) was identified in the first case and an exon 16 deletion was also identified in the second case.

We treated both cases with angiotensin receptor blocker (ARB).

The amount of proteinuria in the first case did not change after ARB therapy, during the follow-up period (1 year). Proteinuria in the woman decreased to half of the baseline level, 1 year after treatment. Glomerular filtration rate was also maintained during the follow-up.

We identified novel mutations in Koreans with an X-linked AS mutation in the COL4A5 gene and an individual phenotype. This is the first report of AS patients with a novel missense mutation and copy number variation.