As a result of higher LH levels, testosterone levels rise in the peripheral testosterone fraction [the fraction outside the BBB] and this explains the various physical attributes of ALS patients like lower Ratio of the index and ring finger lengths (2D:4D ratio), increased incidence of early onset alopecia etc. This deficiency of DHT leads to motor neuron death causing ALS. This evidence concerns the gene PLOD1 and amyotrophic lateral sclerosis.