This web site uses cookies. Do you accept the use of external cookies? Yes No Know more x
Survey about achondroplasia
We have designed a questionnaire with the purpose to better know the population connected to achondroplasia.
The questionnaire is optional and anonymous. The data obtained will be used for statistical purposes and to better understand the natural history of achondroplasia. Please consider answering.
If you would like to take the survey later, you can click on the link at the top "Register at BA"
7th Oct 2019 - The largest European population-based epidemiological study, "Epidemiology of achondroplasia: A population-based study in Europe". was published with data provided by the European Surveillance of Congenital Anomalies (EUROCAT) network. The cases of achondroplasia included in this study were collected from 28 registries in Europe registered between 1991-2015.


epidemiology in ACH

What is epidemiology? 

Epidemiology is the study of how often diseases or conditions occur in different groups of people and why they occur. Epidemiological information is used to plan and evaluate strategies to prevent illness and as a guide to the management of patients in whom the disease has already developed.1

 
Aim of the study

The aims of this study were to investigate the prevalence of different birth outcomes, associated anomalies and the impact of both paternal and maternal age on de novo achondroplasia (new cases), using data from 1991 to 2015, in Europe.

 

The data used was provided by the EUROCAT (European Surveillance of Congenital Anomalies)

  • Cases registered are diagnosed mainly up to one year of age with major structural congenital anomalies, chromosomal abnormalities and genetic syndromes among live births, fetal deaths (FD) with gestational age (GA) ≥ 20 weeks, and terminations of pregnancy for fetal anomaly after prenatal diagnosis at any gestation.
  • Specific details of the methods, definitions and coding instructions of EUROCAT can be accessed in the article.
  • After invitations, twenty-eight EUROCAT registries in 17 European countries enrolled in the study
  • Provided cases of achondroplasia required the birthday to be between January 1, 1991 and December 31, 2015.
  • Data evaluated contained: age at diagnosis, birth outcome, survival up to one week of age, sex, GA in completed weeks, GA at discovery if prenatally diagnosed, birth weight, associated anomalies, family history, and paternal and maternal age at delivery in de novo achondroplasia cases.
 
Prevalence and birth outcomes

Over the 25 years, in a total of 11,402,594 births, 434 cases with achondroplasia were reported, giving an overall prevalence of 3.72 per 100,000 births and a live birth prevalence of 3.05 per 100,000.

  • Results regarding prevalence in Europe countries and locations differed significantly (p-value < 0.05), with the highest values registered in Malta, Paris and Ukraine.
    Percentages of termination of pregnancy differ probably due to cultural and legal situations, which vary across Europe. 40% of the cases (33 in a total of 82) were from just one registry (country).
  • Among cases with known information about family history (n=208), 42 of these confirmed familial cases. The other 166 were de novo cases.
    The mean ages of mothers were 31.2 years, with a standard deviation of 5.6 years. For parents, a mean value of 36.5 years with a standard deviation of 7.7 years.
  • Among cases with available information on the time of diagnosis (n=415), 263 of these were diagnosed prenatally (before birth) and 152 after birth. Of these 152, 24.1% (n=100) were diagnosed at delivery while 3.4% (n=14) were diagnosed during the first week of life. 
  • Among live births with available information on the time of diagnosis (331 cases), 179 (54.1%) of these were diagnosed prenatally.
  • When achondroplasia was discovered prenatally, around 1 out of 3 of parents opted to terminate the pregnancy. An important note is the fact that prenatal detection rate significantly improved when looking by the 5-year periods (from 35.9% in 1991-1995 to 71.0% in 2011-2015).
  • Among live-born infants with available information about survival beyond one week of age (n=280), only five infants died during the first week. The rate of FD was 0.02 per 100,000 births and the rate of early deaths (during the first week) was 0.04, giving a total of perinatal mortality of 0.06 per 100,000 births – a very low value, as expected for a nonlethal skeletal dysplasia as achondroplasia.

 

 20.2% of familial cases and 10.1% of total newborns presented major associated congenital anomalies (44 cases), related to the nervous system, heart defects, and urinary anomalies.
Babies’ mean weight was 2,951 g for males and 2,936 g for females, with delivery being mostly after 39 weeks for both males and females. 

 

 

De novo achondroplasia - new cases

 

In this study, 166 cases of de novo cases were identified out of the 208 cases of achondroplasia with known information about family history.

An analysis was performed (corresponding to 93 cases), in order to assess the association between parental and maternal age and de novo achondroplasia:

  • Fathers in age-groups 35-39 years and 40+ years had a significantly higher risk of de novo achondroplasia when compared to the risk of fathers under 30 years (in line with other published researches);
  • On the other side, maternal age was not associated with de novo achondroplasia, when adjusted for paternal age and for the registry.

Resources
1. BMJ - what is epidemiology
2
. EUROCAT
3
Epidemiology of achondroplasia: A population-based study in Europe
To view this site you need Internet Explorer 8 (or a higher version)
or another internet browser.


Thank You.