TMEM67 and Meckel syndrome: Biallelic truncating pathogenic variants in TMEM67 (MKS3) commonly lead to Meckel syndrome (MKS3, OMIM #607361); however, “milder” TMEM67 allelic combinations (e.g., biallelic missense variants) lead to less severe phenotypic presentations such as JS or isolated NPHP (192, 193).