Trichorhinophalangeal syndrome type II

What it is, symptoms and effects

From: MedlinePlus Genetics, National Library of Medicine

Trichorhinophalangeal syndrome type II (TRPS II) is a condition that causes bone and joint malformations; distinctive facial features; intellectual disability; and abnormalities of the skin, hair, teeth, sweat glands, and nails. The name of the condition describes some of the areas of the body that are commonly affected: hair (tricho-), nose (rhino-), and fingers and toes (phalangeal).

People with this condition have multiple noncancerous (benign) bone tumors called osteochondromas. Affected individuals may develop a few to several hundred osteochondromas. These bone growths typically begin in infancy to early childhood and stop forming around adolescence. Depending on the location of the osteochondromas, they can cause pain, limited range of joint movement, or damage to blood vessels or the spinal cord. Individuals with TRPS II may have reduced bone mineral density (osteopenia). Affected individuals often have slow growth before and after birth resulting in short stature. In TRPS II, the ends (epiphyses) of one or more bones in the fingers or toes are abnormally cone-shaped. Additionally, the fingernails and toenails are typically thin and abnormally formed.

Children with TRPS II often have an unusually large range of joint movement (hypermobility). However, as osteochondromas begin to develop, typically starting between infancy and mid-childhood, the joints begin to stiffen, leading to decreased mobility. Individuals with TRPS II may also have a misalignment of the hip joints (hip dysplasia), which often develops in early adulthood but can occur in infancy or childhood.

The characteristic appearance of individuals with TRPS II involves thick eyebrows; a broad nose with a rounded tip; a long, smooth area between the nose and the upper lip (philtrum); a thin upper lip; and small teeth that are either decreased (oligodontia) or increased (supernumerary) in number. Almost all affected individuals have sparse scalp hair. Males are particularly affected by hair loss, with many being nearly or completely bald soon after puberty. Some children with this condition have loose skin, but the skin becomes tighter over time. Individuals with TRPS II may experience excessive sweating (hyperhidrosis).

Most individuals with TRPS II have mild intellectual disability.

Inheritance

From: MedlinePlus Genetics, National Library of Medicine

Autosomal dominant

Understanding terms used in the source

These definitions explain medical words used above. A definition is not evidence that another condition is present, and it does not predict how a symptom will develop. Ask the clinician which terms apply to the actual examination or test result.

Mild intellectual disability

Mild intellectual disability (ID) is defined as a type of ID characterized by mildly sub-average adaptive functioning and intellectual functioning, with an intelligence quotient (IQ) the range of 50-69.

Reduced bone mineral density

A reduction of bone mineral density, that is, of the amount of matter per cubic centimeter of bones.

Intellectual disability

The term intellectual disability or intellectual developmental disorder is used to describe significantly sub-average intellectual and adaptive functioning based on clinical assessment and as measured by individually administered, appropriately normed, standardized and validated tests of intellectual functioning and adaptive behavior, with onset during the developmental period from infancy through adolescence.

Sparse scalp hair

Decreased number of hairs per unit area of skin of the scalp.

Hyperhidrosis

Abnormal excessive perspiration (sweating) despite the lack of appropriate stimuli like hot and humid weather.

When it may begin

From: MedlinePlus Genetics, National Library of Medicine

These bone growths typically begin in infancy to early childhood and stop forming around adolescence. However, as osteochondromas begin to develop, typically starting between infancy and mid-childhood, the joints begin to stiffen, leading to decreased mobility. Individuals with TRPS II may also have a misalignment of the hip joints (hip dysplasia), which often develops in early adulthood but can occur in infancy or childhood.

Inheritance in the source

From: MedlinePlus Genetics, National Library of Medicine

Autosomal dominant

Understanding the inheritance label

From: MedlinePlus Genetics

An autosomal dominant pattern means that one altered copy of a relevant gene can be sufficient for the condition. Some affected people inherit the change; others have a new change without an affected parent. The precise finding, family history and condition determine what this means for relatives.

Which doctor should you see?

The suggested department for discussing Trichorhinophalangeal syndrome type II 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 Trichorhinophalangeal syndrome type II. 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.