To investigate whether lactate dehydrogenase D (LDHD) gene deficiency causes juvenile-onset gout.We used whole exome sequencing (WES) for two families and a targeted gene-sequencing panel for an isolated patient. D-lactate dosages were analyzed by using ELISA.We demonstrated linkage of juvenile-onset gout to homozygous carriage of 3 rare distinct LDHD variants in 3 different ethnicities. In a Melanesian family, the variant was [NM_153486.3: c(206 C > T); rs1035398551] and, as compared with non-homozygotes, homozygotes had higher hyperuricemia (p= 0.02), lower fractional clearance of urate (FCU) (p= 0.002) and higher levels of D-lactate in blood (p-0.04) and urine (p= 0.06). In a second, Vietnamese, family, very severe juvenile-onset gout was linked to homozygote carriage of an undescribed LDHD variant (NM_153486.3: c.1363dupG) leading to a frameshift followed by a stop codon, p.(AlaGly432fsTer58). Finally, a Moroccan man, with early-onset and high D-lactaturia, whose family was unavailable for testing, was homozygous for another rare LDHD variant [NM_153486.3: c.752C>T, p.(Thr251Met)].Rare, damaging LDHD variants can cause autosomal recessive early-onset gout. the diagnosis of which can be suspected by measuring high D-lactate levels in the blood and/or urine.