Observed total and live birth prevalence of Wolf-Hirschhorn syndrome in England 2015-2020

Background

Birth prevalence estimates for Wolf-Hirschhorn syndrome (WHS) are frequently quoted as either 1 in 50,000, or 1 in 20,000 to 1 in 50,000. The origin of the 1 in 50,000 estimate is obscure whilst the 1 in 20,000 is based on expert opinion. A 2001 UK study of WHS cases reported a minimal live birth prevalence of 1 in 95,896.

Objective

To estimate the total birth and live birth prevalences of Wolf-Hirschhorn Syndrome (WHS) in England between 2015-2020 and compare the results with previously published reports.

Methods

Data on total births and live births were obtained from the English National Congenital Anomaly and Rare Disease Registration Service. Birth prevalence was calculated in two ways: firstly, by dividing the total number of cases of WHS by the total number of births (live births plus stillbirths, miscarriages after 20 weeks and termination of pregnancy); and secondly, by dividing the number of WHS cases resulting in live births by the total number of live births.

Results

There were 56 total births, resulting in 30 live births, identified between 2015 and 2020. Total birth prevalence was 2.16 per 100,000 (95% CI 1.63 – 2.80 per 100,00) equivalent to 1 in 46,303 (95% CI 1 in 35,656 – 1 in 61,297). The live birth prevalence was 1.16 per 100,000 (95% CI 0.78 – 1.66 per 100,00), equivalent to 1 in 86,092 (95% CI 1 in 60,307 – 1 in 127,601) consistent with the earlier UK study. Additionally, the distribution between translocations, deletions and proportion alive at 1 year (86.7%) were also consistent with the earlier UK study.

Conclusion

We believe the frequently quoted WHS birth prevalence figures are an overestimate and recommend that birth prevalence figures are based on empirical data with the nature of the numerator and denominator stated clearly.