How could a difference in a sequence of nucleotides in a gene could result in a boy being albino or having normal skin?

A difference in the sequence of nucleotides in a gene associated with melanin production can lead to variations in skin pigmentation. In the case of albinism, mutations in genes like the TYR gene can disrupt the production of tyrosinase, an enzyme essential for melanin synthesis. As a result, individuals with such mutations have reduced or absent melanin, leading to lighter skin and hair. Conversely, normal nucleotide sequences in these genes would allow for proper melanin production, resulting in typical skin pigmentation.