Lutropin subunit beta is a member of the glycoprotein hormone beta chain family and encodes the beta subunit of luteinizing hormone (LH). Glycoprotein hormones are heterodimers consisting of a common alpha subunit and a unique beta subunit which confers biological specificity. LH is expressed in the pituitary gland and promotes spermatogenesis and ovulation by stimulating the testes and ovaries to synthesize steroids.

The genes for the beta chains of chorionic gonadotropin and for luteinizing hormone are contiguous on chromosome 19q13.3. Mutations in this gene are associated with hypogonadism which is characterized by infertility and pseudohermaphroditism.