Chapter 15.2, Problem 1R

Summary Introduction

To review:

The following, based on the given information,

a. The sequence of amino acid that a mutant allele has produced and whether the mutation is a non-sense, silent, frame-shift or missense.

b. The reason due to which the function of the enzyme gets affected by this mutation.

Given:

The wild-type coding sequence (part) of the HGD (Homogentisate 1, 2-dioxygenase) gene is given as follows:

$\begin{array}{l}\text{Coding sequence …TTG ATA CCC ATT GCC…}\mathrm{..}\hfill \\ \text{Amino acid sequence is … Leu Ile Pro Ile Ala…}\mathrm{..}\hfill \\ \hfill \end{array}$

One of the mutant allele sequences of the HGD gene is provided as follows:

$\begin{array}{l}\text{Coding sequence …TTG ATA TCC ATT GCC}\mathrm{.....}\hfill \\ \text{Amino acid sequence is …}\text{. Leu Ile Ser Ile Ala…}\mathrm{..}\hfill \end{array}$

Introduction:

Alkaptonuria is a genetic disorder. The person who suffers from this disease cannot process the amino acids called phenylalanine and tyrosine. It is produced as a result of a mutation in the gene named had that produce an enzyme HGD. In absence of this enzyme homogentisic acid accumulate in the blood and tissue.