Childhood prevalence of achondroplasia in New South Wales and the Australian Capital Territory, Australia

Abstract

The aim of this study was to estimate the childhood prevalence of achondroplasia, trends over time in birth prevalence, and age at diagnosis in Australia. Children born between 1990 and 2019 with a clinical and radiological and/or molecular diagnosis of achondroplasia were identified from a tertiary hospital servicing New South Wales (NSW) and the Australian Capital Territory (ACT) and compared with population data from the Australian Bureau of Statistics. Childhood prevalence of achondroplasia, based on children ≤19 years of age and resident in NSW/ACT on June 30, 2019 (n = 109), was 5.2 per 100,000. A total of 127 individuals with achondroplasia were born in 1990–2019 in NSW/ACT. Birth prevalence rates increased across birth decades, from 3.3 per 100,000 live births in 1990–1999 to 5.3 per 100,000 in 2010–2019 (p < 0.0001). Median age at diagnosis decreased to 17 days in 2010–2019 compared with 30 days in 1990–1999 (p = 0.035), although the overall decreasing trend across consecutive decades did not reach statistical significance. This is the first study to show a rising birth prevalence rate for achondroplasia in Australia with a concurrent decreasing age at diagnosis, both of which were statistically significant after 2 decades.

Australian guidelines for the management of children with achondroplasia

“…Achondroplasia is the most common form of skeletal dysplasia but remains a rare condition with prevalence in New South Wales (NSW) of 5.2 in 100 000, 1 and 4.6 in 100 000 internationally 2 . It is an autosomal dominant condition caused by mutations in the fibroblast growth factor receptor 3 ( FGFR3 ) gene 3 .…”

“…6,13 International, American and European expert consensus management guidelines have been published, [14][15][16][17] as well as guidelines for specific complications. 1,10,[14][15][16][17][18][19][20][21][22][23][24][25] There are several targeted pharmaceutical treatments for achondroplasia in clinical trials currently (see Supporting Information). BioMarin's Vosoritide has been demonstrated to increase growth velocity in phase 3 trials.…”

“…International, American and European expert consensus management guidelines have been published, 14 , 15 , 16 , 17 as well as guidelines for specific complications. 1 , 10 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25…”

Medical complications in children with achondroplasia

“…An autosomal dominant condition, it is usually diagnosed clinically at birth and confirmed with radiological and/or genetic investigations. The prevalence of achondroplasia in Australia is increasing, with 1 in 20 000 children affected; 2 80% are born to parents of average stature and 99% have the same FGFR3 mutation 2 …”

“…The prevalence of achondroplasia in Australia is increasing, with 1 in 20 000 children affected; 2 80% are born to parents of average stature and 99% have the same FGFR3 mutation. 2 In 1995, the American Academy of Paediatrics (AAP) Committee on Genetics published guidelines on Health Supervision for Children with Achondroplasia, 3 which were updated in 2005 and 2020. 4,5 They outline optimal management for children with achondroplasia, including surveillance and management of complications.…”