Sotos Syndrome Flashcards
What is Sotos syndrome?
Congenital overgrowth disorder
Incidence of Sotos syndrome
1 in 14000
Tatton-Brown & Rahman, 2004
Genetic mutation in Sotos Syndrome
Haploinsufficiency of the nuclear receptor binding SET domain protein 1 (NSD1) gene, located on chromosome 5q35
How many clinically identified cases is the genetic abnormality present in?
90%
Tatton-Brown et al. 2005
Clinical features of SS - cardinal features (Cole & Hughes, 1994)
Overgrowth
Macrocephaly
- Height and/or head circumference > 97%
Advanced bone age
Characteristic facial appearance
Intellectual disability
Clinical features of SS - major features
Scoliosis
Seizures
Cardiac anomalies
Renal anomalies
Hyperlaxity
- Hypermobility of joints
Facial appearance of SS
Sparse hair
Frontal bossing
Down slanting palpebral (relating to the eyes) fissures
Prominent jaw
Brain differences in Sotos syndrome
Schaefer et al. (1997)
Brain scans of 40 children with Sotos
None of the patients had normal MRI scans
Abnormalities in the corpus callosum (especially posterior)
Enlarged ventricles
Inadequate development of posterior white matter
Conclusions from differences in the brain in Sotos
Delayed/disturbed development of the brain, particularly midline structures
Children had normally sized brains in abnormally sized heads
Epilepsy was common
Lane, Milne & Freeth (2016)
Systematic review of Sotos cognitive and behavioural features
Majority of individuals with Sotos have intellectual disability
25 studies assessed cognition using standardised IQ tests
Reported range of IQ scores 21 - 113
Verbal IQ seems to be considerably higher than performance IQ
Specific cognitive abilities are not explored in detail
Lane, Milne & Freeth (2016) - Language
Speech and language delays were reported in 11 studies
Finegan et al. (1994) assessed language in 27 participants with Sotos and matched controls
Found that language abilities were consistent with general level of intellectual functioning
Lane, Milne & Freeth (2016) - behavioural issues
Behavioural problems were reported in 14 studies (11 of these were case studies)
Behavioural profile
Sheth et al. (2015)
Self-injurious behaviour, stereotyped behaviour and destruction of property
Impulsivity and overactivity
Social interaction and impairment
Preference for routine, repetitive questions and repetitive singing/phrases
Methodological considerations of Sheth et al. (2015)
Methodology allows for direct comparison between syndrome groups
Are the behaviours specific to Sotos?
- Syndrome-specific behavioural profile is not clear
Behaviours assessed using questionnaires - findings are based on a parental report
Characteristics of ASD in Sotos syndrome
Lane, Milne & Freeth (2017)
Used social responsiveness scale, 2nd edition
78 participants with Sotos syndrome
65 participants (83.33%) made the clinical cut-off for ASD
There were no gender differences
Age increased likelihood into middle childhood/adolescence and then lessens in adulthood
DSM-5 Subscales in Lane, Milne & Freeth (2017)
More severe diagnoses in the repetitive behaviours and restricted interests sub scale
Suggests that in Sotos this is the most problematic of the ASD symptoms
Five factors of ASD symptoms (Frazier et al., 2014)
Emotional recognition
Social avoidance
Interpersonal relatedness
Insistence on sameness
Repetitive mannerisms
Sotos compared to ASD on the five factors
Very similar results to ASD (high scores on all factors)
Lane et al. (2017) discussion
High prevalence of ASD symptomatology in Sotos syndrome
Symptom severity is affected by age but not gender
Clinical implication - clinicians should screen for ASD in Sotos patients
Further evidence for a genetic mechanism associated with ASD
Cognitive profile of Sotos Syndrome (Lane, Milne & Freeth, 2018)
52 participants used British Abilities Scale (BAS)
- 62% = average intellectual ability
- 23% = borderline intellectual ability
- 15% = intellectual disability
Verbal abilities tended to be higher than non-verbal abilities
- Relative weakness in non-verbal reasoning including quantitative reasoning
Recognition of designs tends to be better than pattern reconstruction abilities
- Relative strength in visuo-spatial memory
Sotos considerations
Children are larger for their age and so can be mistaken as older and more able than their developmental age
High prevalence of ASD in Sotos
Clear and consistent cognitive profile of strengths and weaknesses
- Could be used to create appropriate educational strategies
Systematic review methodology (Lane, Milne & Freeth, 2016)
Identification
- Identified 1304 records through database searching
Screening
- Found 917 records after duplicates were removed
- Excluded 862 articles as they did not give data on cognition or behaviour
Eligibility
- Full text articles were assessed for eligibility = 55
- Excluded 21 as they did not have a means of assessment reported (18), weren’t primary research (2) or weren’t published in English (1)
Included
- Included 34 articles in the systematic review
