Galactosemia (non-digestibility of milk sugar) is inherited in an autosomal recessive manner, occurs with a frequency

Galactosemia (non-digestibility of milk sugar) is inherited in an autosomal recessive manner, occurs with a frequency of 1 in 40,000. Calculate the frequency of occurrence of carriers of the gene for galactosemia.

g (aa) = 1 / 40,000 = 0.000025 g (a) = root of 1 / 40,000 = 0.005
p (A) = 1-0.005 = 0.995, which means the frequency of heterozygotes 2pg = 2 * 0.005 * 0.995 = 0.00995 or 1%
Then:
40,000-100%
X – 1%
x = 400 people are carriers of the galactosemia gene or 40,000: 400 = 100, i.e. the frequency of the heterozygous genotype is 1 per 100.