Carol Naquin and sons
Carol Naquin with her sons Chrisopher and JonathanFacebook

Two brothers from Humble, Texas, who both lost their hearing at primary school, have now been diagnosed with a rare and life-threatening genetic disorder known as Alport Syndrome.

Jonathan Naquin, 18, and Christopher, 16, were finally given a prognosis last summer after years of not knowing what was wrong.

The boys suffered profound and sudden hearing loss in both ears during their primary school years. They were fitted with hearing aids when Jonathan entered third grade and Christopher was in first grade, although doctors were unable to provide a diagnosis.

Throughout their childhood, both boys had consistently tested positive for protein and blood in their urine. Their mother, Carol Naquin, also had the same symptoms. Despite a series of intensive medical examinations, no prognosis was given.

Last summer, Jonathan began to physically decline. At 6 ft 2in, the teenager weighed just 129 pounds and he looked pale and drawn. When he was taken to Texas Children's Hospital, his paediatrician suspected cancer.

However, after further tests Jonathan was diagnosed with Alport Syndrome, a hereditary disease which attacked the kidneys.

Tests have confirmed both boys suffer from the same illness. Jonathan has severe kidney failure and has been placed on an organ transplant list at St. Jude's Hospital in Houston.

What is Alport Syndrome?

Double helix
Alport Syndrome is a rare genetic disorder that mainly affects boysReuters

It is a rare genetic disorder, otherwise known as hereditary nephritis, which is characterised by glomerulonephritis, a severe stage of kidney disease. Hearing loss is another symptom of the disorders, while the presence of blood in the urine is almost always a result of the condition.

It was first identified in a British family by Dr Cecil A. Alport in 1927. The disease attacks the connective tissue of the kidneys, leading to initial symptoms of blood and urine in the urine.

It is caused by genetic mutations that affect the type IV collagen family of proteins.

The ears and eyes share a similar type of tissue to the kidneys, so Alport Syndrome often causes hearing loss and changes to eye structure. Hearing loss is never present at birth but becomes apparent by late childhood or early adolescence, generally before the onset of kidney failure.

Anterior lenticonus is an abnormality in the shape of the eye lens, which affects around 15 to 20% of patients with Alport Syndrome. Patients may need to change the prescription of their glasses frequently and the deterioration of vision may lead to cataract formation.

Recurrent cornea erosion is another eye problem which can occur. Individuals who suffer from this may need to take measures to protect their corneas from minor trauma such as wearing goggles when riding a bicycle.

How many people are affected by the condition?

Alport Syndrome is estimated to effect at least one in 5,000 people. In general, the disease affected boys more than girls because 80% of the time, it is passed on by a mutation on the X chromosome. This is known as X-linked Alport Syndrome. Boys only have one X-chromosome and girls have two, in which the normal chromosome counteracts the effect of the mutated gene.

In the other 20% of Alport Syndrome individuals, boys are affected equally. They have the autosomal recessive or autosomal dominant form of the disease.

What treatment is available?

There is no known cure for the condition and treatments are symptomatic. Patients are advised on how to manage the complications of kidney failure and once it has developed, patients can be given dialysis or may benefit from a kidney transplant.

It is possible that the body may reject the new kidney, as it contains normal type IV collagen, which may not be recognised by the immune system. Gene therapy has been discussed, although the process is still being developed.

Support is available at Alportsyndrome.org and the first Alport Syndrome Awareness month will be held in March 2014.