Lowe syndrome

What it is, symptoms and effects

From: MedlinePlus Genetics, National Library of Medicine

Lowe syndrome is a condition that primarily affects the eyes, brain, and kidneys. This disorder occurs almost exclusively in males.

Infants with Lowe syndrome are born with thick clouding of the lenses in both eyes (congenital cataracts), often with other eye abnormalities that can impair vision. About half of affected infants develop an eye disease called infantile glaucoma, which is characterized by increased pressure within the eyes.

Many individuals with Lowe syndrome have delayed development, and intellectual ability ranges from normal to severely impaired. Behavioral problems and seizures have also been reported in children with this condition. Most affected children have weak muscle tone from birth (neonatal hypotonia), which can contribute to feeding difficulties, problems with breathing, and delayed development of motor skills such as sitting, standing, and walking.

Kidney (renal) abnormalities, most commonly a condition known as renal Fanconi syndrome, frequently develop in individuals with Lowe syndrome. The kidneys play an essential role in maintaining the right amounts of minerals, salts, water, and other substances in the body. In individuals with renal Fanconi syndrome, the kidneys are unable to reabsorb important nutrients into the bloodstream. Instead, the nutrients are excreted in the urine. These kidney problems lead to increased urination, dehydration, and abnormally acidic blood (metabolic acidosis). A loss of salts and nutrients may also impair growth and result in soft, bowed bones (hypophosphatemic rickets), especially in the legs. Progressive kidney problems in older children and adults with Lowe syndrome can lead to life-threatening renal failure and end-stage renal disease (ESRD).

Causes and biological mechanisms

From: MedlinePlus Genetics, National Library of Medicine

Mutations in the OCRL gene cause Lowe syndrome. The OCRL gene provides instructions for making an enzyme that helps modify fat (lipid) molecules called membrane phospholipids. By controlling the levels of specific membrane phospholipids, the OCRL enzyme helps regulate the transport of certain substances to and from the cell membrane. This enzyme is also involved in the regulation of the actin cytoskeleton, which is a network of fibers that make up the cell's structural framework. The actin cytoskeleton has several critical functions, including determining cell shape and allowing cells to move.

Some mutations in the OCRL gene prevent the production of any OCRL enzyme. Other mutations reduce or eliminate the activity of the enzyme or prevent it from interacting with other proteins within the cell. Researchers are working to determine how OCRL mutations cause the characteristic features of Lowe syndrome. Because the OCRL enzyme is present throughout the body, it is unclear why the medical problems associated with this condition are mostly limited to the brain, kidneys, and eyes. It is possible that other enzymes may be able to compensate for the defective OCRL enzyme in unaffected tissues.

Inheritance and family implications

From: MedlinePlus Genetics, National Library of Medicine

This condition is inherited in an X-linked pattern. A condition is considered X-linked if the mutated gene that causes the disorder is located on the X chromosome, one of the two sex chromosomes. In males (who have only one X chromosome), one altered copy of the gene in each cell is sufficient to cause the condition. In females (who have two X chromosomes), a mutation must be present in both copies of the gene to cause the disorder. Most X-linked disorders affect males much more frequently than females. A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons.

In some cases of Lowe syndrome, an affected male inherits the mutation from a mother who carries one altered copy of the OCRL gene. Other cases result from new mutations in the gene and occur in males with no history of the disorder in their family.

Females who carry one mutated copy of the OCRL gene do not have the characteristic features of Lowe syndrome. Most female carriers, however, have changes in the lens of the eye that can be observed with a thorough eye examination. These changes typically do not impair vision.

How common is it?

From: MedlinePlus Genetics, National Library of Medicine

Lowe syndrome is an uncommon condition. It has an estimated prevalence of 1 in 500,000 people.

Reported clinical features and what the terms mean

The following findings are associated with this condition in Orphanet. They are not a checklist for diagnosing yourself, and they do not all occur in every affected person. Some are examination, imaging or laboratory findings that cannot be recognised at home.

The frequency labels describe how often a finding was reported among people with the condition in the source. They do not give the chance that a person with that symptom has the condition. Definitions below reproduce HPO terminology; they explain the term, not the likely severity in an individual.

Abnormal pupil morphology · Very frequent (99-80%)

An abnormality of the pupil.

Abnormal renal tubule morphology · Very frequent (99-80%)

An abnormality of the renal tubules.

Abnormal repetitive mannerisms · Very frequent (99-80%)

Use of the same abnormal action in response to certain triggers or at random. They may be used as a way to regulate one's internal state but must otherwise have no apparent functional purpose.

Amblyopia · Very frequent (99-80%)

Reduced visual acuity that is uncorrectable by lenses in the absence of detectable anatomic defects in the eye or visual pathways.

Aminoaciduria · Very frequent (99-80%)

An increased concentration of an amino acid in the urine.

Anxiety · Very frequent (99-80%)

Intense feelings of nervousness, tension, or panic often arise in response to interpersonal stresses. There is worry about the negative effects of past unpleasant experiences and future negative possibilities. Individuals may feel fearful, apprehensive, or threatened by uncertainty, and they may also have fears of falling apart or losing control.

Aphasia · Very frequent (99-80%)

An acquired language impairment of some or all of the abilities to produce or comprehend speech and to read or write.

Areflexia · Very frequent (99-80%)

Absence of neurologic reflexes such as the knee-jerk reaction.

Other findings in the same source

From: Orphanet

Additional reported features include Cataract (Very frequent (99-80%)); Depression (Very frequent (99-80%)); Glomerulopathy (Very frequent (99-80%)); Hyponatremia (Very frequent (99-80%)); Intellectual disability (Very frequent (99-80%)); Neonatal hypotonia (Very frequent (99-80%)); Nystagmus (Very frequent (99-80%)); Proteinuria (Very frequent (99-80%)); Proximal renal tubular acidosis (Very frequent (99-80%)); Renal insufficiency (Very frequent (99-80%)). This is a selected summary, not a complete description of the condition.

Which doctor should you see?

The suggested department for discussing Lowe syndrome is Clinical Genetics, with a clinical geneticist as the relevant type of clinician. Paediatrician (children) or physician (adults), with clinical geneticist referral.

This is an editorial referral starting point. The appropriate clinic depends on the person’s age, symptoms, previous diagnosis and local services. The first clinician can decide whether another specialty or a team is needed; a department label does not confirm the diagnosis.

How to prepare for an assessment

Bring a short timeline of the main symptoms: when they first appeared, whether they are constant or episodic, what seems to change them, and how they affect daily activities. Include previous reports, discharge summaries, current medicines and supplements, allergies, and any relevant family history. A dated record is more useful than trying to match every feature in an online article.

Ask the clinician what is already established and what remains uncertain. If a test is suggested, ask what question it answers, what its limitations are and how the result would change the next step. The information here is not an instruction to arrange every possible test. In children, bring growth, developmental and school information if it is relevant to the concern.

• Does the exact genetic or chromosome finding explain the observed features?
• Would a genetic counsellor help the family understand the result?
• Which organ-specific assessments are appropriate for this particular diagnosis?

Treatment discussions and follow-up

The material gathered for this draft does not provide a complete condition-specific treatment pathway for Lowe syndrome. That gap does not mean that treatment is unavailable. A clinician needs to establish the diagnosis and review current guidance before recommending medicines, procedures, rehabilitation or other support.

Before leaving the appointment, clarify the next review date, who will communicate results, and whom to contact if the situation changes. Discuss difficulties with sleep, work, school, mobility, eating or emotional wellbeing when these are relevant. Practical support may require coordination between the treating clinician and other services.

The collected references do not establish a complete prevention or long-term outlook section for this entry. Missing information should not be interpreted as proof that prevention is impossible or that a particular outcome is inevitable. Ask what is known for the exact subtype, stage and personal circumstances, and which uncertainties remain.

When to seek emergency help

Severe breathing difficulty, collapse, new stroke-like symptoms, a seizure that is prolonged or repeated without recovery, uncontrolled major bleeding, or an immediate risk of self-harm require emergency help. In India, call 112 or reach the nearest emergency department. This is a general, non-exhaustive warning list; it is not a condition-specific triage tool.