Possibly relevant human trait(s) and/or gene(s)s (MIM numbers): 615986 , 608022

Mendelian trait/disorder: yes

Mode of inheritance: Recessive Embryonic Lethal

Considered a defect: yes

Key variant known: yes

Year key variant first reported: 2018

Species-specific description: Derks et al. (2018) describe "a lethal 212kb deletion with pleiotropic effects on two different genes, one resulting in fetal death in homozygous state (BMPER), and the other increasing growth (BBS9) in heterozygous state. We provide strong evidence for balancing selection resulting in an unexpected high frequency of a lethal allele in the population."

Molecular basis: Derks et al. (2018) identified "a recessive lethal deletion of 212kb (del) within the BBS9 gene in a breeding population of pigs. The deletion produces a truncated BBS9 protein expected to cause a complete loss-of-function, ...[and reduces] expression of the downstream BMPER gene, an essential gene for normal foetal development."

Clinical features: Derks et al. (2018): "Homozygous del/del animals die mid- to late-gestation, as observed from high increase in numbers of mummified piglets resulting from carrier-by-carrier crosses. ...heterozygous carriers exhibit increased growth rate, an important selection trait in pig breeding. Increased growth and appetite together with a lower birth weight for carriers of the BBS9 null allele in pigs is analogous to the phenotype described in human and mouse for (naturally occurring) BBS9 null-mutants."

Associated genes: