Sotos syndrome Flashcards
Sotos syndrome incidence? % of pop with mutation? genetic mutation where? genetic transmission?
congenital overgrowth syndrome, recognised in 1964
(congenital = present from birth)
incidence = 1 in 14000
- genetic mutation = haplosufficiency (mutation on 1 of chromosome pairs= stops it working) of the nuclear receptor binding SET domain protein 1 (NSD1) gene, located chromosome = 5q35 (kurotaki et al)
5 = chromosome
q = long arm
35 = location
abnormality of gene present in approximately 90% of clinically identified cases (Tatton-Brown et al)
severity of the phenotype is variable
- likelihood of passing gene from parent to child (genetic transmission) = child has 50% chance of inheriting mutation as it is on one pair of the chromosome
- if a sibling has sotos syndrome, and you don’t, chance of offspring having it is same as the rest of the population
so, somewhere between 1 in 10,000 and 20,000
Parent account of diagnosis?
some relieved, as it can be challenging to receive diagnosis as its not very well researched
Clinical features
- cardinal features
- major features
- facial features
- cardinal:
overgrowth, macrocephaly(large head - head height/ circumference must be in 97th percentile to gain diagnosis), advanced bone age, characteristic facial appearance, intellectual disability - major:
scoliosis (curvature of spine), seizures, cardiac abnormalities, renal anomalies(kidney problems), hyperlaxity(mobility) - facial:
sparse hair, frontal bossing(pronounced forehead), downslanting palprebal fissures(eyes), prominent jaw
Differences in the brain?
study
Schaffer, Buehler, Lin + Cole, 2007
- brain scans of 40 children with sotos syndrome
none of the patients with sotos syndrome has normal MRI scans
-abnormality of the corpus callosum (connects 2 hemispheres) - especially posterior
- enlarged ventricles
- inadequate development of posterior white matter (compared to neurotypical)
- gyri tend to be deeper than normal
Concluded:(Schaffer et al, 1997)
- delayed/ disturbed development of the brain, particularly midline structures (corpus callosum)
- children had normal sized brains inside abnormally sized heads
- epilepsy is common
Systematic review methodology - Lane et al 2016
- cognitive abilities
- language
34 articles analysed
Cognitive abilities:
- majority of individuals with sotos have an intellectual disability (25/34 assessed cog)
- reported range of IQ scores = 21 (severe) - 113 (above average
- looked at verbal + performance IQ separately
-found: verbal IQ was consistently higher than performance IQ
Language:
-speech and language delays reported in 11 studies
-Finegan et al(1994) assessed language in 27 p’s with sotos
found: language abilties consistent with general level of intellectual functioning
absolute deficit in language ability (as this is lower than the neurotypical population of the same age), however, relative to other deficits they have (eg. quantitative reasoning) language is likely to be a relative strength in comparison
Behavioural issues
behavioural profile?
14 studies
looked at :
aggression, autism, ADHD, anxiety
Behavioural profile (sheth et al)
- self-injurious behaviour, stereotyped behaviour and destruction of property
- impulsivity and over activity (similar to ADHD)
- social interaction impairment
- preference for routine, repetitive questions and repetivite phrases/ signing
Behavioural measures
Measures
- Wesset scale- behavioural profile
- activity questionnaire
- repetitive behaviour questionnaire
- challenging behaviour questionnaire
- mood, interest questionnaire - depression
- social communication Q - autism
Methodology considerations
- methodology allows direct comparisons between syndrome groups
- are these behaviours specific to sotos syndrome? (syndrome-specific behavioural profile isn’t clear)
- behaviours assessed using questionnaires - findings based on parental report (Accurate?)
:Characteristics of ASD in sotos
2 subscales?
overall profile of autism symptoms?
Lane, Milne & Freeth (2007)
social responsiveness scale (65 item) - assesses severity of behaviours in autism
(age appropriate versions)
Total score indicates severity of symptomatology associated with ASD
-DSM-5 specific factors: 2 subscales:
1) social communication impairment
2) restricted interests and repetitive behaviours
- clinical cut-off(where autistic traits observed in an individual are clinically relevant) = 83.33% met this criteria
- v large % of those with sotos syndrome fell into severe range category for ASD
-no sig gender differences
-sig effect of age (Severity increase with age, then decreases again in adulthood)
- on BOTH subscales, individuals appear to be in the severe range, however, repetitive behaviours and restricted interests more problematic with those with Sotos
Overall profile (5 factors)
- emotion recognition, social avoidance, interpersonal relatedness, insistence of sameness, repetitive mannerisms
- those with sotos has v similar results to those with ASD diagnosis
concluded:
- high prevelance of ASD symptomatology in sotos
-symptom severity affected by age, but not gender
-clinical implications: clinicians should screen for ASD in sotos
-further evidence for a genetic mechanism associated with ASD?
Cognitive profile of sotos - Lane et al, 2018
found: general conceptual ability (IQ)
- around 10% in average range
- 20% in borderline category
- 71% in intellectual disability range
looked at:
-verbal/non-verbal reasoning/ spatial reasoning
found:
- verbal abilities tend to be higher than non-verbal
-spatial abilities tend to differ:
recognition of design = good
pattern construction = poor
concluded:
-relative strength in visuo-spatial memory
-relative weakness in non-verbal reasoning, including quantitative reasoning
=clear cognitive profile for sotos syndrome
SO,
-verbal better than non-verbal reasoning ability
-quantitative reasoning = v poor (scores in lower 20th percentile)
-recognition of designs/visuospatial skills better than average
Cognitive or behavioural profile clear?
clear cognitive profile
behavioural profile not v clear yet
Sotos considerations
- children are larger for their age, so can be mistaken as older and more able than their developmental level
- high prevalence of ASD
- clear and consistent cognitive profile of strengths and difficulties –> could be used to create appropriate educational strategies eg. clear planning and structure of sessions
