Alison Barton’s paper on mitigated phenotypes observed in carriers of recessive disease variants (Barton et al. 2022 AJHG) is now published — congratulations, Alison! This work leveraged whole-exome sequencing together with imputation in UK Biobank to identify carrier effects of rare variants known to cause recessive Mendelian diseases in homozygotes. These analyses identified 103 significant associations between quantitative traits and carrier status for 35 unique Mendelian recessive diseases, including a variant in the gene POR implicated in Antley-Bixler syndrome that associated with a 1.76 cm (s.e. 0.27 cm) increase in height. Carriers of the cystic fibrosis Phe508del inframe deletion exhibited increased risk of four disease traits, whereas carriers of SMN1 deletions (which cause spinal muscular atrophy in homozygotes) did not exhibit any evidence of mitigated neuromuscular phenotypes, demonstrating a spectrum of recessiveness even among well-known Mendelian diseases.