Publications by authors named "K Lachlan"

Social attention is a key aspect of neurodevelopment and is significantly altered in neurodevelopmental genetic syndromes and many individuals with idiopathic autism spectrum disorder (ASD). The primary aim of the present study was to examine the psychometric properties of webcam-collected social attention measurements, including four new specific aspects of social attention, in three genetic syndromes (PTEN Hamartoma Tumor Syndrome-PHTS; Malan Syndrome-NFIX; and SYNGAP1-related disorder-SYNGAP1), a mixed group of other neurodevelopmental genetic syndromes (Other NDGS), and individuals with a range of idiopathic neurodevelopmental disorder (NDD). The secondary aim was to evaluate the construct validity of these social attention measurements, including evaluating known-groups validity across study groups and concurrent validity for separating ASD and non-ASD cases.

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Aim: To examine neurobehavioral findings in three genetic syndromes (PTEN hamartoma tumor syndrome, Malan syndrome [mutations in the NFIX gene], and SYNGAP1-related disorder), a mixed group of other neurodevelopmental genetic syndromes (NDGS), idiopathic neurodevelopmental disorder, and neurotypical control participants.

Method: Using a longitudinal case-control design, caregivers reported neurobehavioral information for 498 participants (PTEN hamartoma tumor syndrome n = 112, Malan syndrome n = 24, SYNGAP1-related disorder n = 47, other NDGS n = 72, idiopathic neurodevelopmental disorder n = 54, neurotypical siblings n = 74, and unrelated neurotypical control participants n = 115) at three timepoints (baseline, and 1-month and 4-month follow-ups) using the online-administered Neurobehavioral Evaluation Tool (NET).

Results: NET scales had good scale and test-retest reliability.

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DDX17 is an RNA helicase shown to be involved in critical processes during the early phases of neuronal differentiation. Globally, we compiled a case-series of 11 patients with neurodevelopmental phenotypes harbouring de novo monoallelic variants in DDX17. All 11 patients in our case series had a neurodevelopmental phenotype, whereby intellectual disability, delayed speech and language, and motor delay predominated.

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Article Synopsis
  • ARID1A and ARID1B duplications are linked to Coffin-Siris syndrome, but ARID1B duplications have not been previously associated with a specific clinical phenotype until now.
  • A study analyzed 16 cases of ARID1A and 13 cases of ARID1B duplications, revealing that ARID1A duplications resulted in more severe symptoms, including intellectual disabilities and growth delays, while both groups displayed similar features.
  • The research identified unique DNA methylation patterns in ARID1A duplication patients, which differ from those with loss-of-function variants, suggesting the presence of a distinct clinical phenotype for both ARID1A and ARID1B duplications, indicating a new type of
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GC-rich tandem repeat expansions (TREs) are often associated with DNA methylation, gene silencing and folate-sensitive fragile sites, and underlie several congenital and late-onset disorders. Through a combination of DNA-methylation profiling and tandem repeat genotyping, we identified 24 methylated TREs and investigated their effects on human traits using phenome-wide association studies in 168,641 individuals from the UK Biobank, identifying 156 significant TRE-trait associations involving 17 different TREs. Of these, a GCC expansion in the promoter of AFF3 was associated with a 2.

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