It may be possible to confirm family relationships by comparing test results with Jani or other carriers of his ancestors' Y-chromosome or mitochondrial DNA.
Y-chromosome DNA test-takers in his direct paternal line on WikiTree:
Family Tree DNA Y-DNA Test 111 markers, haplogroup N-BY78895, FTDNA kit #274226
Mitochondrial DNA test-takers in the direct maternal line:
Family Tree DNA mtDNA Test Full Sequence, haplogroup U5b1b1a1a1, FTDNA kit #274226, MitoYDNA ID T10901[compare]