{Reference Type}: Letter {Title}: Diagnostic challenge between a frequent polygenic hypocholesterolemia and an unusual Smith Lemli Opitz syndrome related to bi-allelic DHCR7 mutations. {Author}: Bonnot Ruget M;Moulin P;Pagan C;Cheillan D;Marmontel O;Raverot G;Benlian P;Di Filippo M; {Journal}: Clin Chem Lab Med {Volume}: 62 {Issue}: 9 {Year}: 2024 Aug 27 {Factor}: 8.49 {DOI}: 10.1515/cclm-2024-0162