Data from our carrier screening refine estimates of SLOS carrier frequency in Central Europe

We’re pleased to contribute data from our preconception carrier screening program to refine estimates of the carrier frequency of Smith–Lemli–Opitz syndrome (SLOS) and to better describe the spectrum of pathogenic variants in the DHCR7 gene in Central Europe.

A major value of this type of diagnostics is that, in addition to its direct benefit for individual couples, it also generates high-quality population data that help improve genetic testing and result interpretation in clinical practice.

What we found (Czech + Hungarian data)

• SLOS (DHCR7) carrier frequency: 2.83% (approximately 1 in 35 individuals)

• Top 3 most common pathogenic DHCR7 variants:

  1. c.452G>A (p.Trp151Ter)

  2. c.964-1G>C (splice-site)

  3. c.976G>T (p.Val326Leu)

     
     

• These three variants account for approximately 93.2% of all pathogenic/likely pathogenic alleles detected in our cohort.

Proč je to důležité pro screening

Many panels used in practice target only the most common variants. In our carrier screening, however, we analyze the entire DHCR7 gene, which allows us to detect rarer pathogenic variants that targeted testing could miss. This means higher carrier detection and more accurate risk assessment for couples.

For illustration: if a test covered only the 3 most common variants, the theoretical residual carrier risk after a negative result in the studied population would be about 0.19% (≈ 1:522). Comprehensive analysis of the full gene reduces this residual risk further

📄 Publication (MDPI Genes): https://www.mdpi.com/2073-4425/17/2/164