Clinical Guidance

No clinically relevant genotype-phenotype correlations have been observed.

Source: GeneReviews — "Troyer Syndrome"

Diagnostic Criteria

No consensus clinical diagnostic criteria for Troyer syndrome have been published.

Suggestive Findings

Troyer syndrome should be suspected in probands with the following clinical and imaging findings and family history.

Clinical findings

• Developmental delay in early infancy/ childhood: poor feeding, swallowing difficulties, delayed speech, delayed walking

• Childhood-onset spastic paraplegia

• Symmetric amyotrophy of the small muscles of hands and feet

• Progressive dysarthria and persistent drooling

• Learning difficulties

• Emotional lability

• Short stature

Additional clinical findings

Source: GeneReviews — "Troyer Syndrome"

Differential Diagnosis

Troyer syndrome shares some features with Silver syndrome, ARSACS (autosomal recessive spastic ataxia of Charlevoix-Saguenay), and Silver-Russell syndrome . Table 2. Genetic Disorders of Interest in the Differential Diagnosis of Troyer Syndrome

Management Guidelines

No clinical practice guidelines for Troyer syndrome have been published. In the absence of published guidelines, the following recommendations are based on the authors' personal experience managing individuals with this disorder.

Evaluations Following Initial Diagnosis

To establish the extent of disease and needs of an individual diagnosed with Troyer syndrome, the evaluations summarized (if not performed as part of the evaluation that led to the diagnosis) are recommended.

Table 3.

Troyer Syndrome: Recommended Evaluations Following Initial Diagnosis

System/Concern | Evaluation | Comment

Growth/Nutrition

| Growth assessment incl height, weight, head circumference |

Gastroenterology/ nutrition/ feeding team eval | • To incl eval of aspiration risk nutritional status

• Consider eval for gastrostomy tube placement in persons w/dysphagia /or aspiration risk.

Development

| Developmental assessment | • To incl motor, adaptive, cognitive, speech-language eval; incl assessment for dysarthria tongue dyspraxia

• Eval for early intervention/ special education

Neurologic

| Consultation w/neurologist | To assess for ataxia, pyramidal /or extrapyramidal movement disorders, distal amyotrophy, hyperreflexia, swallowing difficulties

Neurobehavioral/

Psychiatric

| Psychological assessment, w/attention to presence or absence of emotional lability |

Skeletal

| • Physical exam for skeletal abnormalities

• Radiographs for kyphoscoliosis as needed

|

Genetic counseling

| By genetics professionals1 | To obtain a pedigree inform ...

Source: GeneReviews — "Troyer Syndrome"

Clinical Guidance

Dantrolene should be avoided in persons who are ambulatory as it may induce irreversible weakness, which can adversely interfere with overall mobility.

Source: GeneReviews — "Troyer Syndrome"

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 — "Troyer Syndrome"

Surveillance Guidelines

To monitor existing manifestations, the individual's response to supportive care, and the emergence of new manifestations, the evaluations summarized in are recommended. Table 5. Troyer Syndrome: Recommended Surveillance

Source: GeneReviews — "Troyer Syndrome"