JOUBERT
SYNDROME |
ALTERNATE NAMES
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Agenesis of Cerebellar Vermis; Cerebello-Oculo-Renal Syndrome; Cerebellooculorenal
Syndrome 1; Cerebelloparenchymal Disorder 4; Joubert-Bolthauser Syndrome; Joubert
Syndrome and Related Disorders; Joubert Syndrome Type A; Pure Joubert Syndrome; Classic
Joubert Syndrome; JS
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DESCRIPTION
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Joubert Syndrome
(JS) is a rare genetic disorder of brain development that may affect many parts of the
body. It is characterized by the absence or underdevelopment of the cerebellar vermis
(a part of the brain that controls balance and coordination) and a malformed brain
stem (connection between the brain and spinal cord). JS appears to be inherited in
an autosomal recessive manner (meaning both parents must have a copy of the mutation)
via mutation in a number of genes, including NPHP1, AHI1, and CEP290. JS typically has an autosomal X-linked recessive pattern of inheritance.
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DIAGNOSTIC TESTING, PHYSICAL FINDINGS, AND
ICD-9-CM/ICD-10-CM
CODING
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Diagnostic testing: The diagnosis for JS is established by a combination of:
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Clinical examination and imaging studies of the midbrain and pons that resemble the
characteristic molar tooth sign;
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Genetic testing for mutations in the NPHP1, CEP290, AHI1, TMEM67 (MKS3), RPGRIP1L, CC2D2A, ARL13B, INPP5E, OFD1, TMEM216, KIF7, TCTN1,
TCTN2, TMEM237, CEP41, TMEM138, C5orf42, TMEM231, or TCTN3 genes.
Physical
findings: JS may be seen in isolation or may be related to several other disorders including
retinal dystrophy, renal disease, and other abnormalities. Infants with JS may have:
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Abnormally large head (macrocephaly);
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Ptosis (drooping or falling upper eyelid);
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Upturned nose with prominent nostrils;
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Cerebellar and brain stem malformation resulting in "molar tooth" sign seen on imaging;
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Hypotonia (decreased muscle tone) in infancy;
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Ocular colobomas (missing pieces of tissues in or around the eye);
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Polydactyl (extra fingers and toes);
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Oral hamartomas (nodules of mature cells and tissues);
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Rapid breathing (hyperpnea);
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Decreased muscle tone (hypotonia);
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Jerky eye movements (oculomotor apraxia);
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Intellectual impairment; and
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Inability to coordinate voluntary muscle movements (ataxia);
ICD-9:
759.89
ICD-10: G11.1
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PROGRESSION
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Prognosis for children with Joubert Syndrome depends on the severity of the condition.
The prognosis for infants with JS depends on whether or not the cerebellar vermis
is partially developed or entirely absent. In some cases, the cerebellar vermis is
almost fully developed, resulting in mild symptoms. The mildest form of the disease
often results in mild lapses in motor control and mild intellectual disability. These
individuals can live full, productive lives with medical and familial support.
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TREATMENT
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There is no definitive treatment available for JS. Treatment is supportive and symptom
specific. Infants and children with abnormal breathing may require stimulatory medications;
supplemental oxygen; mechanical support; or tracheostomy in rare cases. Other interventions
may include speech therapy; occupational and physical therapy; educational support
including special programs for the visually impaired; and feedings by gastrostomy
tube. Surgery may be required for polydactyl and symptomatic ptosis or strabismus.
End-stage renal disease, liver failure or fibrosis is treated with standard medical
approaches. Children may require annual evaluations of growth, vision, and liver and
kidney function and, periodic neuropsychological and developmental testing.
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SUGGESTED PROGRAMMATIC ASSESSMENT*
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Suggested MER for Evaluation:
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Clinical history and examination that describes the diagnostic features of the impairment
and laboratory findings are needed to confirm the diagnosis; and
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Developmental assessment or psychological testing to address allegations of mental
impairment may be warranted.
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Suggested Listings for
Evaluation: |
DETERMINATION
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LISTING
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REMARKS
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Meets |
111.07
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111.17
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112.05
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Equals |
112.02 |
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* Adjudicators may, at their discretion, use the Medical Evidence of Record or the
listings suggested to evaluate the claim. However, the decision to allow or deny the
claim rests with the adjudicator.
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