Is this a simple Hardy-Weinberg problem? Phenylketonuria is a severe developmental disability due to a rare autosomal recessive allele. Approximately 1 in every 10,000 newborns suffer from this disease. Calculate the frequency of the allele causing this disease and the frequency of heterozygous "carrier" individuals. What I've come up with is that this is a Hardy-Weinberg problem. Is this true? My answers: frequency of allele causing disease = 0.01 frequency of heterozygous "carrier" individuals = 0.0198

Yes, your answers are correct. Of course, your calculations forced you to make the standard Hardy-Weinberg assumptions such as random mating. Good job!