Urinalysis and Body Fluids 6th Edition by Majorie DiLorenzo, Susan Strasinger

Exercise 7

An overflow disorder that could produce a false-positive reaction with Clinitest procedure is:

A. Cystinuria

B. Alkaptonuria

C. Indicanuria

D. Porphyrinuria

Step 1 of 2

Overflow disorders:

Over flow disorders are caused due to disturbance in metabolic pathway, which causes increased nonmetabolized substances in plasma.

• The disorder included in over flow type are,

o Maple syrup urine disease

o Cystinosis

o Porphyria

o Galactosemia

o Alkaptonuria

o Phenylketonuria

o Organic acidemias

o Lesch-Nyhan disease

o Mucopolysaccharidoses

o Tyrosinemia

o Phenylketonuria

Alkaptonuria:

• This is the third chief disorder in phenylalanine-tyrosine pathway

• Failure to inherit of homogentisic acid oxidase enzyme causes this disorder

• Without this enzyme, the phenylalanine-tyrosine pathway does not get completed as homogentisic acid collects in urine, blood, and tissues

• Homogentisic acid produces false positive reaction in Clinitest to give yellow precipitate that indicates reducing substances

Therefore, over flow disorder “alkaptonuria” could produce false positive reaction in Clinitest procedure. Hence, the correct answer is option.