“…Because SNPs with larger effects are easier to identify in gene mapping studies, and prediction tools based on a limited number of SNPs can easily be developed, FDP systems for eye, hair and skin colour prediction from trace DNA have already been developed and forensically validated [5,6] Widening appearance DNA prediction beyond pigmentation traits is generally troubled by the absence of major gene effects in non-pigmentation appearance traits, thus requiring a much larger number of DNA predictors due to their small phenotypic effects [7][8][9]. Recent progress illustrated, as is theoretically expected, that when genome-wide association studies (GWASs) based on increased sample size are applied for appearance traits, larger numbers of genome-wide significant SNPs with small effects are found, such as shown for hair structure [7], hairloss in men [8,10], hair colour [11], and skin colour [12]. Moreover, it has been demonstrated recently for hair structure [13], hairloss in men [10], and hair colour [11] that when the enlarged numbers of identified SNPs are applied in prediction studies, they provide increased prediction accuracies compared to earlier models based on fewer numbers of SNPs [14,15].…”