Is Benedict test positive in alkaptonuria?

Reducing sugar, Ascorbic acid, High level of uric acid or glucuronide may give Benedict’s test positive. Result should be counter checked with Uristrip / Dipstrip for Glucose. Alkaptonuria gives Uristrip test negative.

What are the causes of alkaptonuria?

Alkaptonuria is caused by mutation of the homogentisate 1,2-dioxygenase (HGD) gene. The HGD gene contains instructions for creating (encoding) an enzyme known as homogentisate 1,2-dioxygenase. This enzyme is essential for the breakdown of homogentisic acid.

What happens alkaptonuria?

Alkaptonuria, or “black urine disease”, is a very rare inherited disorder that prevents the body fully breaking down two protein building blocks (amino acids) called tyrosine and phenylalanine. It results in a build-up of a chemical called homogentisic acid in the body.

What is the most likely reason that alkaptonuria is a recessive disease?

Alkaptonuria is an autosomal recessive disorder caused by a deficiency of the enzyme homogentisate 1,2-dioxygenase. This enzyme deficiency results in increased levels of homogentisic acid, a product of tyrosine and phenylalanine metabolism.

Can disaccharides be reducing sugars?

Disaccharides are formed from two monosaccharides and can be classified as either reducing or nonreducing. The aldehyde functional group allows the sugar to act as a reducing agent, for example, in the Tollens’ test or Benedict’s test.

What are non carbohydrate reducing substances?

These sugars include galactose, lactose, and fructose. However, Clinitest, which involves the reduction of colorless cupric ion to colored cuprous ion, is not specific for sugars. Many drugs produce a positive result [3].

Is alkaptonuria fatal?

Alkaptonuria patients develop arthritis and often suffer from other diseases too, including cardiovascular and kidney disease. Fatal alkaptonuria cases are infrequent, and death often results from kidney or cardiac complications.

How common is alkaptonuria?

This condition is rare, affecting 1 in 250,000 to 1 million people worldwide. Alkaptonuria is more common in certain areas of Slovakia (where it has an incidence of about 1 in 19,000 people) and in the Dominican Republic.

What tests can be used to diagnose alkaptonuria?

Your doctor can use a test called gas chromatography to look for traces of homogentisic acid in your urine. They can also use DNA testing to check for the mutated HGD gene. Family history is very useful in making a diagnosis of alkaptonuria.

What causes alkaptonuria and what are the symptoms?

What are the Causes of Alkaptonuria? Alkaptonuria is caused by mutations in the HGD gene, which encodes the enzyme homogentisate 1,2-dioxygenase (HGD). This enzyme helps breakdown the amino acids phenylalanine and tyrosine, which are important building blocks of proteins.

How is alkaptonuria related to the HGD gene?

Alkaptonuria is caused by mutations in the HGD gene. The HGD gene codes for the enzyme required for the breakdown of homogentisic acid. Alkaptonuria is inherited in an autosomal recessive fashion 1). Alkaptonuria does not cause developmental delays or cognitive impairment and does not appear to affect life span.

How does homogentisate 1, 2 dioxygenase cause alkaptonuria?

It is caused by a mutation in the HGD gene for the enzyme homogentisate 1,2-dioxygenase ( EC 1.13.11.5 ); if a person inherits abnormal copies from each parent (it is a recessive condition ), the body accumulates an intermediate substance called homogentisic acid in the blood and tissues.

How is echocardiography used to diagnose alkaptonuria?

With echocardiography, sound waves are bounced off the heart (echoes), enabling physicians to study cardiac function and motion. Computed tomography (CT) scan may be recommended to detect coronary artery calcification. The treatment of alkaptonuria is aimed at the specific symptoms that are present in each individual.