Diagnosing of chromosome abnormalities in Denmark

Area of Science:

• Medical Genetics
• Cytogenetics
• Public Health

Background:

• Chromosome abnormalities pose significant health challenges.
• Accurate prenatal and postnatal diagnosis is crucial for management.
• Denmark's cytogenetic diagnostic rates from 1970-1980 were previously unassessed.

Purpose of the Study:

• To survey the frequency of diagnosed chromosome abnormalities in Denmark.
• To compare diagnosed rates with expected incidences (1970-1980).
• To evaluate the effectiveness of prenatal diagnosis and abortion in managing chromosomal disorders.

Main Methods:

• Analysis of data from the Danish Cytogenetic Central Register.
• Comparison of diagnosed cases with expected incidences of chromosomal abnormalities.
• Review of prenatal diagnosis and induced abortion rates for specific conditions.

Main Results:

• Only 13% of expected sex chromosome abnormalities were diagnosed, with significant underdiagnosis of Klinefelter's syndrome (10%).
• Down's syndrome diagnosis reached 90% by chromosome examination, with prenatal diagnosis and abortion increasing to 20% by 1977-1980.
• Overall, 39% of expected chromosomal abnormalities were diagnosed postnatally and 10% prenatally by January 1, 1983.

Conclusions:

• Significant underdiagnosis of chromosome abnormalities occurred in Denmark during the study period.
• There is a critical need for enhanced clinical genetics training and expanded, decentralized cytogenetic services.
• Increased employment of clinical geneticists across all Danish counties is recommended to improve diagnostic rates.