Clinical Guidance

Data are inadequate to reliably correlate clinical severity to a specific TRAPPC2 pathogenic variant. All pathogenic variants identified thus far, irrespective of their molecular basis, result in an almost identical phenotype, including the true null variants.

Source: GeneReviews — "X-Linked Spondyloepiphyseal Dysplasia Tarda"

Diagnostic Criteria

No consensus clinical diagnostic criteria for X-linked spondyloepiphyseal dysplasia tarda have been published.

Suggestive Findings

X-linked spondyloepiphyseal dysplasia tarda (X-linked SEDT) should be suspected in males with the following findings:

Source: GeneReviews — "X-Linked Spondyloepiphyseal Dysplasia Tarda"

Differential Diagnosis

X-linked spondyloepiphyseal dysplasia tarda (X-linked SEDT) is distinguished from other forms of spondyloepiphyseal dysplasia (SED) by its later onset and X-linked inheritance . Table 2. Forms of Spondyloepiphyseal Dysplasia of Interest in the Differential Diagnosis of X-Linked Spondyloepiphyseal Dysplasia Tarda

Management Guidelines

Evaluations Following Initial Diagnosis

To establish the extent of disease and needs in an individual diagnosed with X-linked spondyloepiphyseal dysplasia tarda (X-linked SEDT), the evaluations summarized (if not performed as part of the evaluation that led to the diagnosis) are recommended:

Table 3.

Recommended Evaluations Following Initial Diagnosis in Individuals with X-linked Spondyloepiphyseal Dysplasia Tarda

System/Concern | Evaluation | Comment

Skeleton

| Complete radiographic survey to incl scoliosis series if clinically indicated | To assess extent of skeletal manifestations

Cervical spine

| • Flexion-extension radiographs of cervical spine

• Flexion-extension MRI if instability compression seen on radiographs or interpretation on radiographs is limited (e.g., in young persons w/delayed ossification in upper cervical spine)

| To assess for clinically significant odontoid hypoplasia

Genetic

counseling | By genetics professionals1 | To inform affected persons their families re nature, MOI, implications of SEDT to facilitate medical personal decision making

MOI = mode of inheritance

1. Medical geneticist, certified genetic counselor, certified advanced genetic nurse

Treatment of Manifestations

Table 4.

Treatment of Manifestations in Individuals with X-linked Spondyloepiphyseal Dysplasia Tarda

Manifestation/Concern | Treatment | Considerations/Other

Odontoid

Source: GeneReviews — "X-Linked Spondyloepiphyseal Dysplasia Tarda"

Clinical Guidance

The following should be avoided:

• In individuals with odontoid hypoplasia, extreme neck flexion and extension

• Activities and occupations that place undue stress on the spine and weight-bearing joints

Source: GeneReviews — "X-Linked Spondyloepiphyseal Dysplasia Tarda"

Therapies Under Investigation

Search ClinicalTrials.gov in the US and EU Clinical Trials Register in Europe for access to information on clinical studies for a wide range of diseases and conditions. Note: There may not be clinical trials for this disorder.

Source: GeneReviews — "X-Linked Spondyloepiphyseal Dysplasia Tarda"

Surveillance Guidelines

Table 5. Recommended Surveillance for Individuals with X-linked Spondyloepiphyseal Dysplasia Tarda

Source: GeneReviews — "X-Linked Spondyloepiphyseal Dysplasia Tarda"