Pseudohypoparathyroidism type 1B

What it is

From: Orphanet

Pseudohypoparathyroidism type 1B (PHP-1b) is a type of pseudohypoparathyroidism (PHP) characterized by localized resistance to parathyroid hormone (PTH) mainly in the renal tissues which manifests with hypocalcemia, hyperphosphatemia and elevated PTH levels. About 60-70% of patients also present with elevated TSH levels due to TSH resistance.

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.

Elevated circulating parathyroid hormone level · Very frequent (99-80%)

An abnormal increased concentration of parathyroid hormone.

Hyperphosphatemia · Very frequent (99-80%)

The concentration of phosphate ion in the blood circulation is above the upper limit of normal.

Hypocalcemia · Very frequent (99-80%)

The concentration of calcium in the blood circulation is below the lower limit of normal.

Pseudohypoparathyroidism · Obligate (100%)

A condition characterized by resistance to the action of parathyroid hormone, in which there is hypocalcemia, hyperphosphatemia, and (appropriately) high levels of parathyroid hormone.

Low urinary cyclic AMP response to PTH administration · Very frequent (99-80%)

Cataract · Frequent (79-30%)

A cataract is an opacity or clouding that develops in the crystalline lens of the eye or in its capsule.

Delayed eruption of teeth · Frequent (79-30%)

Delayed tooth eruption, which can be defined as tooth eruption more than 2 SD beyond the mean eruption age.

Depressed nasal bridge · Frequent (79-30%)

Posterior positioning of the nasal root in relation to the overall facial profile for age.

Enamel hypoplasia · Frequent (79-30%)

Developmental hypoplasia of the dental enamel.

Full cheeks · Frequent (79-30%)

Increased prominence or roundness of soft tissues between zygomata and mandible.

Nystagmus · Frequent (79-30%)

Rhythmic, involuntary oscillations of one or both eyes related to abnormality in fixation, conjugate gaze, or vestibular mechanisms.

Round face · Frequent (79-30%)

The facial appearance is more circular than usual as viewed from the front.

Short neck · Frequent (79-30%)

Diminished length of the neck.

Short stature · Frequent (79-30%)

A height below that which is expected according to age and gender norms. Although there is no universally accepted definition of short stature, many refer to "short stature" as height more than 2 standard deviations below the mean for age and gender (or below the 3rd percentile for age and gender dependent norms).

Other findings in the same source

From: Orphanet

Additional reported features include Abdominal symptom (Occasional (29-5%)); Anxiety (Occasional (29-5%)); Chest pain (Occasional (29-5%)); Conjunctivitis (Occasional (29-5%)); Depression (Occasional (29-5%)); Diaphyseal sclerosis (Occasional (29-5%)); Dyskinesia (Occasional (29-5%)); Dyspnea (Occasional (29-5%)); Hypocalcemic tetany (Occasional (29-5%)); Hyporeflexia (Occasional (29-5%)). This is a selected summary, not a complete description of the condition.

When it may begin

From: Orphanet

Adolescent; Childhood; Infancy; Neonatal

Inheritance in the source

From: Orphanet

Autosomal dominant; Not applicable

Frequency and the population described

From: Orphanet

Point prevalence: Unknown; Europe; Class only.

Which doctor should you see?

The suggested department for discussing Pseudohypoparathyroidism type 1B 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 Pseudohypoparathyroidism type 1B. 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.