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thanatophoric dysplasia - Clinical Profile, Genes & Research | Kisho | Kisho

Rare Disease

thanatophoric dysplasia

MONDO:0017042

Also known as:FGFR3-related thanatophoric dysplasiaTDthanatophoric dwarfism

Overview

A primary bone dysplasia with micromelia characterized by macrocephaly, narrow thorax, and distinctive facial features. It includes TD, type 1 (TD1) and TD, type 2 (TD2), that can be differentiated from each other by femur and skull shape.

OnsetANTENATAL

Clinical Presentation

Built from Human Phenotype Ontology (HPO) phenotype annotations and GeneReviews clinical descriptions. Features represent findings documented across known cases — not an exhaustive list of possible symptoms.

No HPO annotations are available for this condition.

Age of onset: before birth.

GeneReviews

Clinical Guidance

The clinical and radiographic features of thanatophoric dysplasia (TD) types 1 and 2 are evident prenatally or in the immediate newborn period. Respiratory insufficiency typically results in early neonatal death, and is due to a small chest cavity and/or foramen magnum narrowing with brain stem compression. However, long-term survivors have been reported, including rare reports of survival to adulthood with aggressive ventilatory support and surgical management of neurologic complications. To date, more than 200 individuals with TD have been identified with a pathogenic variant in FGFR3 . The following description of the phenotypic features associated with this condition is based on these reports. Table 2. Select Features of Thanatophoric Dysplasia

Diagnosis

Drawn from GeneReviews diagnostic guidelines, newborn screening panel status (RUSP), and ClinGen gene-disease validity classifications. Reflects current clinical evidence and consensus where available.

GeneReviews

Diagnostic Criteria

Formal diagnostic criteria for thanatophoric dysplasia (TD) have not been established.

Suggestive Findings

TD should be suspected in a fetus with the following prenatal imaging findings, or a neonate with the following clinical and radiographic features. Prenatal ultrasound examination [, , , ] findings by trimester:

Source: GeneReviews — "Thanatophoric Dysplasia"

Treatment

Compiled from FDA-approved drug records, orphan drug designations, and FDA Adverse Event Reporting System (FAERS) safety data. GeneReviews management guidance is included where available.

No approved treatments are currently available for thanatophoric dysplasia. The disease remains an area of unmet medical need.

GeneReviews

Management Guidelines

Evaluations Following Initial Diagnosis Diagnosis of thanatophoric dysplasia (TD) most often occurs prenatally. When TD has been diagnosed prenatally, referral should be made to a maternal-fetal medicine specialist for assessment and management advice . Long-term survivors are rare and require aggressive intervention for complications of the condition. The family should be informed of prognosis on the basis of the reports of complications in long-term survivors. , , and are only relevant to the small number of long-term survivors. To establish the extent of disease and needs in a newborn diagnosed with thanatophoric dysplasia (TD), the evaluations summarized (if not performed as part of the evaluation that led to the diagnosis) are recommended. Table 6. Recommended Evaluations Following Initial Diagnosis in Individuals with Thanatophoric Dysplasia

Prognosis

Based on GeneReviews surveillance recommendations, HPO phenotype frequency and severity annotations, and published prevalence estimates from Orphanet and OMIM.

GeneReviews

Surveillance Guidelines

Table 8.

Recommended Surveillance for Individuals with Thanatophoric Dysplasia

System/Concern | Evaluation | Frequency

Respiratory

insufficiency | • Assessment of respiratory status

Neuroimaging in event of respiratory deterioration to evaluate for compression of brain stem at craniocervical junction

Research Landscape

Sourced from ClinicalTrials.gov and PubMed. Publication types are classified using NLM-curated article metadata; research type breakdowns reflect the nature of published work for this disease.

No clinical trials have been registered for thanatophoric dysplasia.

15 publications have been identified in PubMed for thanatophoric dysplasia. Research spans Case Report / Case Series (67%), Diagnostic / Biomarker (13%), and Epidemiology / Natural History (13%).

Research Type	Count	% of Total
Patient case studies	10	67%

Data assembled from 4 of 12 sources · Last updated Sep 20, 2026, 3:05 PM UTC

MONDOHPOClinicalTrials.govFDAPubMedHGNCClinVarClinGenGeneReviewsOrphanetOMIMRUSP

Medical References

External Resources

Orphanet

European rare disease database

Orphanet:2655

GARD

Genetic and Rare Diseases Info Center

GARD:85

Questions for Your Care Team

→Are there specialists or centers of excellence for this condition in my area?
→Is there a patient registry I should consider joining?

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Feature	% of Persons w/Feature	Comment
Respiratory insufficiency	100%	Long-term survivors have all required mechanical ventilation.
Foramen magnum narrowing	~100%1	—
Temporal lobe dysplasia	~100%1,2	—
Hydrocephalus	56%2	—
Cloverleaf skull (multiple craniosynostosis)	100% in persons w/TD type 2; rarely in persons w/TD type 1	—
Dysmorphic facial features	100%	Frontal bossing, flat facies, depressed nasal bridge, ocular proptosis
Relative macrocephaly	100%	—
Growth deficiency	100%	Birth length well 3rd centile; Birth weight head circumference may be normal, but growth restriction of these parameters occurs in infancy childhood.
Bowed femurs	100% in persons w/TD type 1; absent in persons w/TD type 2	—
Survival past age 1 yr	5 persons3	Reports exist of long-term survivors into adulthood, all of whom have required long-term mechanical ventilation. 1. 2. 3. Respiratory insufficiency. Most affected infants die of respiratory insufficiency in the first hours or days of life.

Differential Diagnosis

Table 5. Other Genes of Interest in the Differential Diagnosis of Thanatophoric Dysplasia

Gene(s)	Disorder	MOI	Features of Differential Diagnosis Disorder
WDR35	Skeletal ciliopathies: incl perinatal lethal short-rib polydactyly syndromes Jeune asphyxiating thoracic dystrophy (See OMIM PS208500.)	ARDigenic1	May be lethal in perinatal period or infancy; Narrow thorax short ribs; short stature short limbs noted in infancy (But survivors may manifest only mild-to-moderate short stature.)
COL1A2	Perinatally lethal osteogenesis imperfecta3 (previously OI type II) (See COL1A1/2-OI.)	AD	Typically lethal in perinatal period
TRIP11	Achondrogenesis (ACG) type IA, type IB, type II (OMIM PS200600)	ARAD	Typically lethal in perinatal period; Short stature w/micromelia, relative macrocephaly, short ribs, brachydactyly
COL2A1	Platyspondylic lethal skeletal dysplasia, Torrance type (PLSD-T)4 (OMIM 151210)	AD	Typically lethal in perinatal period; Short long bones w/ragged metaphyses, platyspondyly, short ribs
FGFR3	Homozygous achondroplasia	Codominant	See .

Source: GeneReviews — "Thanatophoric Dysplasia"

System/Concern	Evaluation	Comment
abnormalities	Head spine CT or MRI	Brain stem compression may contribute to respiratory insufficiency.; Cervical myelopathy may quadriplegia.
Craniosynostosis	Head CT in persons w/clinical evidence of craniosynostosis	—
Seizures	Consider assessment w/neurologist /or EEG if episodes suspicious for seizures.	—
Audiology	Audiologic assessment	—
Ophthalmology	Ophthalmology eval for exotropia	—
Developmental delay	Developmental assessment	—
Genetic counseling	By genetics professional1	To obtain a pedigree inform affected persons families re nature, MOI, implications of TD to facilitate medical personal decision making Family support resources
Treatment of Manifestations in Individuals with Thanatophoric Dysplasia Manifestation/Concern	Treatment	Considerations/Other
Respiratory insufficiency	Neonates typically require aggressive respiratory support (e.g., ventilation, tracheostomy) to survive.	1 long-term survivor required supplemental oxygen in neonatal period ventilatory support from age 2 mos.1 Perioperative management2
Hydrocephalus	Eval by neurosurgeon for shunt placement	Craniocervical junction constriction
Seizures	Standard anti-seizure treatment	—
Hearing impairment	Hearing aids per audiologist /or otolaryngologist	—
Vision	Mgmt of exotropia by ophthalmologist	—
Development	Individualized developmental support by allied health clinicians	1. 2. Consensus perioperative management guidelines for individuals with skeletal dysplasia have been published . 3. Surveillance Table 8.

Kisho

thanatophoric dysplasia

Overview

Clinical Presentation

Clinical Guidance

Diagnosis

Diagnostic Criteria

Suggestive Findings

Treatment

Management Guidelines

Prognosis

Surveillance Guidelines

Research Landscape

Medical References

External Resources

Orphanet

GARD

Questions for Your Care Team

Questions for Your Care Team

Differential Diagnosis

Therapies Under Investigation

Clinical Trials

Hearing impairment

Vision

Development

Recent Publications

thanatophoric dysplasia

Overview

Clinical Presentation

Clinical Guidance

Diagnosis

Diagnostic Criteria

Suggestive Findings

Treatment

Management Guidelines

Prognosis

Surveillance Guidelines

Research Landscape

Medical References

External Resources

Orphanet

GARD

Subtypes

Related Diseases

Questions for Your Care Team

Questions for Your Care Team

Differential Diagnosis

Therapies Under Investigation

Clinical Trials

Hearing impairment

Vision

Development

Recent Publications