Histidinemia is a rare hereditary metabolic disorder characterized by a deficiency of the enzyme histidase, which is necessary for the metabolism of the amino acid histidine. The concentration of histidine is elevated in the blood. Excessive amounts of histidine, imidazole pyruvic acid, and other imidazole metabolism products are excreted in the urine. The majority of individuals with histidinemia have no obvious symptoms that would indicate that a person has this disorder (asymptomatic). Histidinemia is inherited as an autosomal recessive trait.

In most cases, people with this condition have no health problems and may not even know that they are affected. Individuals with histidinemia who also experience a medical complication during or shortly after birth (such as a temporary lack of oxygen) may be at an increased risk of developing intellectual disability, behavioral problems, or learning disabilities

Histidinemia is caused by changes (mutations) in the HAL gene. This gene provides instructions for making an enzyme called histidase, which breaks down histidine into a molecule called urocanic acid. If histidase doesn’t do its job properly, histidine levels become elevated. Histidinemia is inherited in an autosomal recessive pattern.

Because there are no symptoms associated with this condition, treatment is not necessary.

Histidinemia is a genetic disease caused by an autosomal recessive metabolic disorder. It is characterized by deficient production of the enzyme that breaks down histidine. It is usually a benign condition and asymptomatic in most cases.

• Usually, a genetic disorder will not tend to have any causative factor other than its inheritance.
• There are some risk factors associated with this case. Consanguineal marriages within the families having this particular disease history is one of the risk factors.
• This will cause inbreeding within the group which will increase the occurrences and severity of the disease.
• The next important risk factor is age. It is usually severe if the patients start to show the symptoms at an early age.
• When the same disease shows its presence in adulthood, the problems are comparatively low.
• Histidinemia is often associated with histidinuria which is the excessive presence of amino acid histidine in the urine.
• Patients with an incidence of urinary tract infections or kidney ailments will have a higher risk of this disease.
• Even for the patients who have a benign condition of the disease, if they get diabetes, heart issues, or any other ailments, their histidinemia tends to exacerbate.
• This will heighten the symptoms presented in the disease.
• The best way to keep the disease in control is to follow a low histidine diet and proper lifestyle habits.

Conditions
Intellectual disability,Behavioral problems,Learning disorders
Drugs
Therapies,Histidine-restricted diet,Genetic counseling
Symptoms
Mostly asymptomatic,Sometimes show hyperactivity,Speech impediment,Developmental delay,Learning difficulties,Sometimes mental retardation

Histidinemia is a condition caused by an inborn metabolic error mechanism. It is caused by a gene-induced deficiency of the enzyme histidase, which processes the amino acid histamine in the body.

• The disease is more or less asymptomatic in its presentation.
• It is usually caught during the routine neonatal screening procedure and other ailments.
• The disease presents symptoms like excessive production of histidine amino acid in the urine.
• When the condition is presented along with any medical complication soon after birth, it can lead to some developmental disabilities and low intelligent quotient in the patients.
• Histidinemia is a rare genetic condition that is often without any symptoms or cure.
• It is caused due genetic mutations and other changes. So this disease cannot be treated or prevented.
• If the persons tend to show the symptoms of the disease, the doctors may recommend the patient to go on a diet with a low histidine level.
• This will reduce the histidine level in the blood.
• When a histidnemia patient consumes a histidine-rich diet, the body will not have the ability to process all of them.
• The second and most important part of the treatment plan is genetic counseling and planning of pregnancies to avoid further instances of this disease in their progeny in the future.
• Consanguineous marriages are also recommended to be avoided by the patients since it is a recessive condition.

Conditions
Intellectual disability,Behavioral problems,Learning disorders
Drugs
Therapies,Histidine-restricted diet,Genetic counseling
Symptoms
Mostly asymptomatic,Sometimes show hyperactivity,Speech impediment,Developmental delay,Learning difficulties,Sometimes mental retardation