hyperprolinemia

What is Hyperprolinemia?

Hyperprolinemia is a rare genetic disorder characterized by an excess of proline, a particular protein building block (amino acid), in the blood. This condition occurs when there is a deficiency or malfunction of the enzyme responsible for breaking down proline.

Types of Hyperprolinemia

There are two main types of hyperprolinemia: Type I and Type II. Both types result from an autosomal recessive inheritance pattern, meaning that a person must inherit one defective gene from each parent to develop the condition [4][9].

• Type I (HPI): This type is caused by a deficiency of the enzyme proline oxidase (POX), also known as proline dehydrogenase. It is characterized by high levels of proline in the blood and often associated with intellectual disability [6].
• Type II: This type results from an excess of proline in the blood due to a different genetic mutation, but the exact mechanism is not well understood.

Symptoms and Diagnosis

The symptoms of hyperprolinemia can vary depending on the severity of the condition. They may include:

• Elevated levels of proline in the blood
• Intellectual disability or developmental delays
• Seizures or other neurological problems

Diagnosis is typically made through a specialized blood test that measures proline levels [5].

References

[1] Aug 27, 2021 — Hyperprolinemia is an excess of a particular protein building block (amino acid), called proline, in the blood. [3] Hyperprolinemia type 2 results in an excess of a particular protein building block (amino acid), called proline, in the blood. [4] by H Mitsubuchi · 2014 · Cited by 41 — Hyperprolinemia type I (HPI) results from a deficiency of proline oxidase (POX; enzyme commission no. [EC] 1.5.99.8), also called proline ... [5] Hyperprolinaemia type I is diagnosed through a specialized blood test. The disorder is identified by raised blood proline levels. [6] a hereditary metabolic disorder characterized by an abnormally high concentration of proline in the blood and often associated with intellectual disability ... [7] Jul 24, 2021 — Hyperprolinemia is defined by elevated proline levels in blood. Hyperprolinemia is divided in primary hyperprolinemia, a metabolic disorder ... [8] Hyperprolinemia is an excess of a particular protein building block (amino acid), called proline, in the blood. This condition generally occurs when proline ...

Common Signs and Symptoms of Hyperprolinemia

Hyperprolinemia, a rare inherited metabolic disorder, can manifest in various ways, affecting individuals differently. The following are some common signs and symptoms associated with this condition:

• Seizures: Individuals with hyperprolinemia type I may experience seizures, which can be a significant concern for their overall health [3].
• Intellectual Disability: Some people with hyperprolinemia may exhibit intellectual disability or developmental delays, impacting their cognitive abilities [5][6].
• Neurological Problems: The condition can also lead to various neurological problems, including global developmental delay, seizures, and other related issues [6].
• Psychiatric Problems: In some cases, individuals with hyperprolinemia type I may experience psychiatric problems, such as anxiety or depression [3].
• Recurrent Skin Lesions: A distinctive feature of hyperprolinemia is the presence of recurrent, poorly healing, ulcerative skin lesions. These can occur anywhere on the body but are often found in areas prone to friction [7].

It's essential to note that not everyone with hyperprolinemia will exhibit these symptoms, and some individuals may remain asymptomatic despite having elevated proline levels in their blood [8]. However, for those who do experience symptoms, it's crucial to seek medical attention for proper diagnosis and management.

References: [3] Aug 27, 2021 - Some individuals with hyperprolinemia type I exhibit seizures, intellectual disability, or other neurological or psychiatric problems. [5] May 22, 2008 - Hyperprolinemia Type I (HP-I) is characterized by high levels of proline in the blood resulting from a deficiency of the enzyme proline oxidase, ... [6] The reported clinical phenotype ranges from asymptomatic to variable neurologic and psychiatric manifestations (including global developmental delay, seizures, ... [7] The most prominent and consistent finding is recurrent, poorly healing, ulcerative skin lesions. Although ulcerations can occur anywhere, they are usually ... [8] People with hyperprolinemia type I often do not show any symptoms, although they have proline levels in their blood between 3 and 10 times the normal level.

Diagnostic Tests for Hyperprolinemia

Hyperprolinemia, also known as elevated proline levels in the blood, can be diagnosed through various tests that measure the levels of proline and related compounds in the blood or urine.

• Newborn Screening: Newborn screening programs can detect hyperprolinemia type II by measuring amino acids in whole blood samples collected on specialized filter paper [3].
• Blood Test: A blood test can measure the levels of proline and a related compound, P-5-C, to diagnose hyperprolinaemia type II [6].
• Urine Test: A urine test can also detect raised levels of proline and P-5-C in the urine to diagnose hyperprolinaemia type II [6].
• Genetic Testing: Genetic testing, such as the Invitae Elevated Proline (Hyperprolinemia) Panel, analyzes genes associated with elevations of proline on newborn screening or plasma samples [9].

Follow-up Testing

After an initial test, follow-up testing is necessary to confirm if a baby has hyperprolinemia or not. This may involve checking the baby's urine and blood samples for signs of prolinemia (PRO) [10].

Note: The primary marker for diagnosis of HPI is an elevated proline in plasma or urine amino acid profiles [7].

Treatment Options for Hyperprolinemia

Hyperprolinemia, a rare genetic disorder characterized by an excess of proline in the blood, can be managed through various treatment approaches. While there is no cure for this condition, dietary therapy and antioxidant therapy have been explored as potential treatments.

• Dietary Therapy: Restricting proline intake has been suggested as a possible treatment approach for hyperprolinemia (3). This involves modifying one's diet to minimize the consumption of proline-rich foods.
• Antioxidant Therapy: Some studies have investigated the use of antioxidants, such as coenzyme Q10 and B complex vitamins, in managing hyperprolinemia (4). These supplements may help alleviate symptoms by reducing oxidative stress.

It is essential to note that treatment for hyperprolinemia can vary depending on the specific type and severity of the condition. In some cases, no treatment may be necessary, as the disorder may not cause significant clinical manifestations (5).

References:

• [3] Treatment and prognosis. Treatment of the hyperprolinemia seen in HPI has included dietary therapy such as the restriction of proline.
• [4] by M Ersoy · 2021 · Cited by 2 — We started antioxidant therapy with 100 mg/d coenzyme Q10 and B complex (B1 + B2 + B6 + B12), 500 mg ...
• [5] Treatment. At present time, iminoglycinuria is considered an incidental finding and no treatment is necessary.

Differential Diagnosis of Hyperprolinemia

Hyperprolinemia, a condition characterized by an excess of the amino acid proline in the blood, can be challenging to diagnose due to its similarities with other disorders. A differential diagnosis is essential to rule out other conditions and confirm hyperprolinemia.

Similarities with Other Disorders:

• Hyperprolinemia Type II (HPII): This condition is characterized by a level of proline in