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And : Cognive ability & Cognive disabilies

Q: Which form doesn't has familial resemblance? (cognitive disability)

Moderate en severe cognitive disability

Q: Characteristics males with FRX

IQ declines after childhood Large, protruding ears Long face with prominent jaw Unusual behavior

Q: Characteristics of Rett Syndrome (RS)

Males do not survive it because it is on the X chromosome Happens to 1 in 10.000 females First year: normal development Regression occurs between 1 and 4 years. Problemens with language, coordination and repetitive movements

Q: Cause Rett syndrome (RS)

Mutation of the MECP2 gene (on the X chromosome). This encodes the methyl-CpG binding protein-2. MECP2 regulates BDNF.

Q: Definition duchenne muscular dystrophy (DMD) and effect on IQ

Disorder of the muscle tissue caused by a recessive gene on the X chromosome. Occurs in 1 of the 3500 males and death before the age of 20. Average IQ is 80.

Q: Definition Lesch-Nyhan syndrome and effect on IQ

Disorder with many medical problems including self-injury caused by a recessive gene on the X chromosome. Occurs 1 in 20.000 males, death before 30. Average IQ is 70.

32 important questions on And : Cognive ability & Cognive disabilies

Where is IQ a good predictor for?

Social, educational and occupational outcome

What is the correlation for g for twins who where adopted apart?

Between 0.72 and 0.78

What is the correlation for adoptive siblings?

0.32. Thus 1/3 of the variance is explained by C

Which traits are correlated with g?

Executive function and working memory
Reaction time
Brain volume
Thinning of the cerebral cortex during adolescents
Structural measures of connectivity
Less brain activation (more efficient)

ACE components for reading and math skills:

A: 0.5
C: 0.3
E: 0.2

Division general cognitive disability

Mild general cognitive disability: 50 - 70
Moderate general cognitive disability 35 - 50
Severe general cognitive disability 20 - 35
Profound general cognitive disability < 20

Which form doesn't has familial resemblance? (cognitive disability)

Moderate en severe cognitive disability

Characteristics males with FRX

IQ declines after childhood
Large, protruding ears
Long face with prominent jaw
Unusual behavior

Characteristics of Rett Syndrome (RS)

Males do not survive it because it is on the X chromosome
Happens to 1 in 10.000 females
First year: normal development
Regression occurs between 1 and 4 years.
Problemens with language, coordination and repetitive movements

Cause Rett syndrome (RS)

Mutation of the MECP2 gene (on the X chromosome). This encodes the methyl-CpG binding protein-2. MECP2 regulates BDNF.

Definition duchenne muscular dystrophy (DMD) and effect on IQ

Disorder of the muscle tissue caused by a recessive gene on the X chromosome. Occurs in 1 of the 3500 males and death before the age of 20. Average IQ is 80.

Definition Lesch-Nyhan syndrome and effect on IQ

Disorder with many medical problems including self-injury caused by a recessive gene on the X chromosome. Occurs 1 in 20.000 males, death before 30. Average IQ is 70.

Definition neurofibromatosis type 1 (NF1) and effects on IQ.

Disorder that leads to skin tumors and tumors in nerve tissue caused by a single dominant allele. Start showing symptoms at a middle age (after reproduction). Occurs 1 in 3000. Average IQ is 85.

What is the most important cause of general cognitive disability ?

Down syndrome (1 in 1000)

Symptoms down syndrome (DS)

Increased neck tissue
Muscle weakness
Speckled iris of the eye
Open mouth
Protruding tongue
cognitive disability (IQ 55)
Short stature

Definition Klinefelter syndrome (XXY male syndrome)

Syndrome with low testosterone levels leading to infertility, small testes and breast development. Occurs 1 in 500 males and average IQ is 85.

Definition triple X syndrome (XXX)

Syndrome with speech problems due to an extra X chromosome in females. Occurs 1 in 1000 females. Average IQ is 85.

Where leads an extra y chromosome to?

Taller males, normal sexual development, but some speech difficulties and reading problems. Occurs 1 in 1000 males and average IQ is 10 points lowers than siblings.

Defintion Angelman syndrome

Small deletion of chromosome 15 in the mother egg. Leads to:

Moderate cognitive disability
Abnormal gait
Speech impairment
Seizures
Inappropriately happy demeanor
De novo

Defintion Williams syndrome

Small deletion of chromosome 7. Leads to disorders of connective tissue that lead to grow retardation and medical problems. Average IQ is 55. Occurs 1 in 10.000 births. Usually de novo.

Definition non-zero spousal correlation

For a specif trait, the couple is more correlated than two random people.

Affect of additive genetic variance on parent-offspring study

You overestimate the heritabilty because you overestimate the correlation between parents and the child

Affect of additive genetic variance on twin model

Assortative mating increases DZ correlation but not MZ correlation. This means that A is underestimated and C is overestimated.

Affect of additive genetic variance on GWAS

It increases the genetic variance in the population. So there is an overestimation of the SNP heritability.

Disadvantage candidate gene approach

Problem is that is does not replicate

What is the difference between achievement and ability?

Achievement: implies effort
ability: based on genetic influence

What is the generalist genes hypothesis?

Most genes associated with common learning disabilities are generalists meaning that:
1. Genes that affect common learning disabilities are largely the same genes responsible for normal variation in learning abilities
2. Genes that affect one learning disability are also likely to affect other learning disabilities

Which 3 genetic findings are special for cognitive abilities?

1. Heritabilty increases during development
2. Assortative mating is substantial
3. The same genes affect diverse cognitive and learning abilities

How is it possible that heritability increases during development?

Genetic amplification: a process where genetic nudges early in development are magnified as time goes by, with the same genetic factors creating larger and larger phenotypic effects

What is an exception of heritability increasing during development?

School achievement

What is assortative mating?

The phenotypic correlation between spouses. You choose someone who is similar to you

What is the major strategy for finding genes associated with cognitive abilities and the genetic correlations among them?

Increase the sample size of GWA analyses

The question on the page originate from the summary of the following study material:

Twin Research in Psychology

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