Turner Syndrome Flashcards
What is TS?
TS is a neurodevelopmental disorder that affects 1 in 2000 female births.
TS is one of the most common chromosomal disorders in woman. As well as effecting physical appearance, amenorrhea (no periods) and fertility, the disorder causes relatively strong verbal IQ, deficits in visuospatial perception and memory, motor abilities and attentional processes.
Psychosocial skills are commonly impaired in TS, and studies have shown this is not purely a result of familial environment.
There are currently two treatment options available including growth hormone treatment in childhood and oestrogen replacement therapy in adolescence.
What are the deficits associated with TS?
Physical deficits include a webbed neck, low set ears and hairline and heart, kidney and thyroid problem - subject to peer teasing about body - significant predictor of depression
Poor social competence due to low self esteem
Deficits and delays reaching sexual milestones
Non-verbal impairments of autism are very similar to TS
Explain genetic cause of TS
In normal women (46XX) one of the two X chromosomes is randomly inactivated.
Haploinsufficiency of these genes in women with TS (45X) is presumed to play a role in determining the TS phenotype.
The parent of origin of the intact X chromosome may also affect the phenotype of classical TS, providing support for imprinted loci on the X chromosome.
Women with TS whose maternal X chromosome is active tend to perform more poorly on measures of social cognition and adjustment than those whose parental X chromosome is active but verbal IQ was significantly lower in those with paternal X chromosome than maternal.
Emotion recognition and gaze following
Impaired in TS women - significant impairment in face recognition irrespective of depressed IQ score
Especially in fear and surprise - amygdala appears to be the cause
Fail the Frith-Happe animation so may result from ToM deficits
Gaze is not globally impaired but accuracy deteriorates when face does not provide a clue
Elgar et al (2002)
Found when asked to identify where a face is looking TS women perform worse than TD men and women for both allocentric tasks (where is she looking) and egocentric tasks (is she looking at you), they also made less fixation on eyes in free viewing tasks (Mazzola et al 2006).
Role of amygdala in TS
Crucial role in social cognition especially processing of emotionally salient visual information and has been implicated in emotion recognition.
The findings that support and contradict amygdala volume being correlated the number of chromosome X present.
The left and right amygdala differ in their function with the right dominant in autonomic response and the left in processes triggered by such stimuli.
