Disease pattern among 942 mentally retarded persons in a Danish county

Area of Science:

• Public Health
• Epidemiology
• Genetics

Background:

• Intellectual disability affects a significant portion of the population, with diverse etiological factors.
• Understanding the prevalence and characteristics of intellectual disability is crucial for resource allocation and support services.

Purpose of the Study:

• To provide an analytical description of individuals with intellectual disability in West Zealand.
• To determine the prevalence of intellectual disability in the region.
• To identify important etiological factors and associated conditions.

Main Methods:

• Analytical description of 942 individuals diagnosed with intellectual disability (IQ below 75).
• Data collection included demographic information, etiological factors, and co-occurring conditions.
• Prevalence calculation based on registered cases within the specified region.

Main Results:

• The prevalence of intellectual disability was found to be 0.36% in West Zealand.
• Nearly half of the individuals resided in institutions; 43% were female and 57% male.
• Significant etiological factors included a positive family history (nearly one-third), being born as the fourth or subsequent child (30%), and advanced maternal age (>35 years) at birth (one-sixth).
• Down's syndrome was diagnosed in 22% of patients with IQs below 50.
• Epilepsy and cerebral palsy were present in 17% and 11% of patients, respectively.
• All patients in the central institution experienced psychiatric or somatic complications.

Conclusions:

• Intellectual disability in West Zealand presents with a prevalence of 0.36%, with a notable proportion requiring institutional care.
• Genetic factors, birth order, and maternal age are significant contributors to intellectual disability.
• High rates of co-occurring conditions like Down's syndrome, epilepsy, and cerebral palsy necessitate comprehensive care strategies.