Donohue syndrome

What it is, symptoms and effects

From: MedlinePlus Genetics, National Library of Medicine

Donohue syndrome is a rare disorder characterized by severe insulin resistance, a condition in which the body's tissues and organs do not respond properly to the hormone insulin. Insulin normally helps regulate blood sugar levels by controlling how much sugar (in the form of glucose) is passed from the bloodstream into cells to be used as energy. Severe insulin resistance leads to problems with regulating blood glucose levels and affects the development and function of organs and tissues throughout the body.

Severe insulin resistance underlies the varied signs and symptoms of Donohue syndrome. Individuals with Donohue syndrome are unusually small starting before birth, and affected infants do not grow and gain weight at the expected rate (faltering weight). Additional features that become apparent soon after birth include a lack of fatty tissue under the skin (subcutaneous fat); wasting (atrophy) of muscles; excessive body hair growth (hirsutism); multiple cysts on the ovaries in females; and enlargement of the nipples, genitalia, kidneys, heart, and other organs. Most affected individuals also have a skin condition called acanthosis nigricans, in which the skin in body folds and creases becomes thick, dark, and velvety. Distinctive facial features in people with Donohue syndrome include bulging eyes, thick lips, upturned nostrils, and low-set ears. Affected individuals develop recurrent, life-threatening infections beginning in infancy.

Donohue syndrome is one of a group of related conditions described as inherited severe insulin resistance syndromes. These disorders, which also include Rabson-Mendenhall syndrome and type A insulin resistance syndrome, are considered part of a spectrum. Donohue syndrome represents the most severe end of the spectrum; most children with this condition do not survive beyond age 2.

Causes and biological mechanisms

From: MedlinePlus Genetics, National Library of Medicine

Donohue syndrome results from mutations in the INSR gene. This gene provides instructions for making a protein called an insulin receptor, which is found in many types of cells. Insulin receptors are embedded in the outer membrane surrounding the cell, where they attach (bind) to insulin circulating in the bloodstream. This binding triggers signaling pathways that influence many cell functions.

The INSR gene mutations that cause Donohue syndrome greatly reduce the number of insulin receptors that reach the cell membrane or disrupt the function of these receptors. Although insulin is present in the bloodstream, without functional receptors it cannot exert its effects on cells and tissues. This severe resistance to the effects of insulin impairs blood glucose regulation and affects many aspects of development in people with Donohue syndrome.

Inheritance and family implications

From: MedlinePlus Genetics, National Library of Medicine

This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.

How common is it?

From: MedlinePlus Genetics, National Library of Medicine

Donohue syndrome is estimated to affect less than 1 per million people worldwide. Several dozen cases have been reported in the medical literature.

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.

Hyperkeratosis · Very frequent (99-80%)

Hyperkeratosis is a histopathological term defining a thickened stratum corneum and may be present in many different skin conditions, with many possible overlaps. Hyperkeratosis refers to the increased thickness of the stratum corneum, the outer layer of the skin. Hyperkeratosis is subclassified as orthokeratotic or parakeratotic. Orthokeratotic hyperkeratosis refers to the thickening of the keratin layer with preserved keratinocyte maturation, while parakeratotic hyperkeratosis shows retained nuclei as a sign of delayed maturation of keratinocytes.

Hypertrichosis · Very frequent (99-80%)

Hypertrichosis is increased hair growth that is abnormal in quantity or location.

Insulin resistance · Very frequent (99-80%)

Increased resistance towards insulin, that is, diminished effectiveness of insulin in reducing blood glucose levels.

Postnatal growth retardation · Very frequent (99-80%)

Slow or limited growth after birth.

Postprandial hyperglycemia · Very frequent (99-80%)

An increased concentration of glucose in the blood following a meal.

Reduced subcutaneous adipose tissue · Very frequent (99-80%)

A reduced amount of fat tissue in the lowest layer of the integument. This feature can be appreciated by a reduced skinfold thickness.

Severe intrauterine growth retardation · Very frequent (99-80%)

Intrauterine growth retardation that is 4 or more standard deviations below average, corrected for sex and gestational age.

Fasting hypoglycemia · Very frequent (99-80%)

Other findings in the same source

From: Orphanet

Additional reported features include Abdominal distention (Frequent (79-30%)); Acanthosis nigricans (Frequent (79-30%)); Clitoral hypertrophy (Frequent (79-30%)); Decreased body weight (Frequent (79-30%)); Enlarged kidney (Frequent (79-30%)); Facial hypertrichosis (Frequent (79-30%)); Failure to thrive (Frequent (79-30%)); Hepatomegaly (Frequent (79-30%)); Hyperinsulinemia (Frequent (79-30%)); Hypertrophic cardiomyopathy (Frequent (79-30%)). This is a selected summary, not a complete description of the condition.

Which doctor should you see?

The suggested department for discussing Donohue syndrome is Endocrinology, with a endocrinologist as the relevant type of clinician. General physician / Family Medicine; paediatrician for children. Referral depends on symptoms.

Additional services that may be relevant, depending on the findings, include: Clinical Genetics.

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.

• Which hormone or metabolic finding is important in this case?
• How should test timing and current medicines be taken into account?
• What follow-up would show whether the care plan is working?

Treatment discussions and follow-up

The material gathered for this draft does not provide a complete condition-specific treatment pathway for Donohue 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.