The high allelic frequency of some risk conferring variants in the TANGL cohort allowed the detection of individuals who were homozygous by descent and raised the hypothesis of consanguinity between their parents, as was the case for the two families with recessive dementias [TBK1 c.1717C>T (p.Arg573Cys) and FIG4 c.122 T>C (p.Ile41Thr)]. This evidence concerns the gene FIG4 and dementia.