Prevalence and aetiology of congenitally deafblind people in Denmark

Abstract

A study of prevalence and aetiology was performed on 63 children and 127 adults in Denmark with congenital deafblindness. Using a Scandinavian definition of deafblindness, the prevalence of congenital deafblindness was found to be 1:29 000. Thirty-five different aetiological causes of deafblindness were found. Causes of congenital deafblindness were different among adults compared to causes among children. Rubella syndrome (28%, n = 36) and Down syndrome (8%. n = 10) were the largest groups among people above 18 years of age. Among children CHARGE syndrome (16%, n = 13) was the largest group. Ethnicity was also evaluated. Among children 72% were Danish, but among the adults 98% were Danish. Implications of difference in aetiology and ethnicity are discussed in relation to the Scandinavian traditions of clinical practice and identification of congenital deafblindness.

Identification of congenital deafblindness

“…All individuals known to be congenitally deafblind and had been referred to The Danish Centre for Deafblindness from hospitals and institutions nationwide were included in this study. This amounted to 190 children and adults, the same population as reported on in a former survey study (Dammeyer, 2010). This population of 190 accounts for all the individuals with congenital deafblindness known by The Danish Resource Centre for Congenital Deafblindness.…”

Cognitive capacities and composite cognitive skills in individuals with Usher syndrome type 1 and 2

“…Syndromes causing DB typically have low prevalence (Dammeyer, 2010;Möller, 2007), and in a country with a small population, like Sweden, there will only be small populations. Some syndromes, such as Alström syndrome (AS), will only have a few individuals within each generation (Frölander et al, 2014).…”

Congenital rubella syndrome and delayed manifestations

“…This amounted to 123 individuals. The people included were recruited from a national survey study of prevalence and aetiology [23]. A functional definition of deafblindness was used [24] worked out in a screening method developed by Andersen and Rødbroe [25] in two parts: Part 1.…”