A multi-level developmental approach to exploring individual differences in Down syndrome: genes, brain, behaviour, and environment

摘要: In this article, we focus on the causes of individual differences in Down syndrome (DS), exemplifying multi-level, multi-method, lifespan developmental approach advocated by Karmiloff-Smith (1998, 2009, 2012, 2016). We evaluate possibility linking variations infant and child development with (elevated) risk for Alzheimer's disease (AD) adults DS. review theoretical basis argument, considering genetics, epigenetics, brain, behaviour environment. studies 1 2, variation language development. utilise data from MacArthur-Bates Communicative Development Inventories (CDI; Fenson et al., 2007), Mullen Scales Early Learning (MSEL) receptive productive subscales (Mullen, 1995) 84 infants children DS (mean age 2;3, range 0;7 to 5;3). As expected, there was delay both expressive vocabulary wide differences. Study examined influence an environmental measure (socio-economic status as measured parental occupation) observed variability. SES did not predict a reliable amount variation. 2 predictive power specific genetic (apolipoprotein APOE genotype) which modulates AD adulthood. There no effect genotype, though weak evidence that faster genotype conferring greater (e4 carriers), consistent recent observations attention (D'Souza, Mason 2020). 3 considered concerted early brain describe new magnetic resonance imaging methods measuring prenatal neonatal structure (e.g., volumes supratentorial cortex, cerebellar volume; Patkee 2019). establish methodological viability measures cognitive development, MSEL, potential marker clinical relevance. Five case are presented proof concept, but these yet too few discern pattern.