Phocomelia, Schinzel type

What it is

From: Orphanet

A rare genetic syndrome with limb reduction defects characterized by skeletal malformations comprising absent or hypoplastic pelvic bones (including sacral agenesis or hypoplasia), intercalary limb deficiencies (phocomelia potentially combined with polydactyly, oligodactyly or ectrodactyly), and skull defects (frequently a defect of the occipital bone with or without meningocele). Additional features may include thoracic dystrophy, dysmorphic facial features (dysplastic and large ears, and a high and narrow palate), and genital malformations (Mullerian aplasia, agenesis of the uterus and vagina, micropenis with cryptorchidism). Growth and mental development are not affected.

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.

Abnormality of tibia morphology · Very frequent (99-80%)

Abnormality of the tibia (shinbone).

Absent ulna · Very frequent (99-80%)

Missing ulna bone associated with congenital failure of development.

Aplasia/Hypoplasia of the sacrum · Very frequent (99-80%)

Aplasia or developmental hypoplasia of the sacral bone.

Bowing of the long bones · Very frequent (99-80%)

A bending or abnormal curvature of a long bone.

Disproportionate short stature · Very frequent (99-80%)

A kind of short stature in which different regions of the body are shortened to differing extents.

Ectrodactyly · Very frequent (99-80%)

A condition in which middle parts of the hands and/or feet (digits and meta-carpals and -tarsals) are missing giving a cleft appearance. The severity is very variable ranging from slightly hypoplastic 3rd toe/fingers over absent 2nd or 3rd toes/fingers as far as oligo- or monodactyl hands and/or feet.

Fibular aplasia · Very frequent (99-80%)

Absence of the fibula.

Finger aplasia · Very frequent (99-80%)

A developmental defect resulting in the presence of fewer than the normal number of fingers (i.e., aplasia of one or more fingers).

Foot oligodactyly · Very frequent (99-80%)

A developmental defect resulting in the presence of fewer than the normal number of toes.

Micromelia · Very frequent (99-80%)

The presence of abnormally small extremities.

Nail dysplasia · Very frequent (99-80%)

The presence of developmental dysplasia of the nail.

Aplasia/Hypoplasia involving the pelvis · Very frequent (99-80%)

Aplasia of the uterus · Frequent (79-30%)

A congenital defect characterized by absence of the uterus. Aplasia refers to the failure of an organ to develop during embryonic growth and development due to the absence of primordial tissue.

Hypoplasia of the radius · Frequent (79-30%)

Underdevelopment of the radius.

Other findings in the same source

From: Orphanet

Additional reported features include Intrauterine growth retardation (Frequent (79-30%)); Micrognathia (Frequent (79-30%)); Radial bowing (Frequent (79-30%)); Short neck (Frequent (79-30%)); Anal atresia (Occasional (29-5%)); Cleft palate (Occasional (29-5%)); Cryptorchidism (Occasional (29-5%)); High, narrow palate (Occasional (29-5%)); Humeroradial synostosis (Occasional (29-5%)); Hydrops fetalis (Occasional (29-5%)). This is a selected summary, not a complete description of the condition.

When it may begin

From: Orphanet

Antenatal; Infancy; Neonatal

Inheritance in the source

From: Orphanet

Autosomal recessive

Understanding the inheritance label

From: MedlinePlus Genetics

An autosomal recessive pattern usually involves disease-causing changes in both copies of a gene. Parents may each carry one altered copy without having the condition themselves. A genetic counsellor can explain carrier testing and reproductive implications using the actual laboratory findings, rather than the condition name alone.

Which doctor should you see?

The suggested department for discussing Phocomelia, Schinzel type 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 Phocomelia, Schinzel type. 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.