JOUBERT SYNDROME
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ALTERNATE NAMES
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Agenesis of Cerebellar Vermis; Cerebello-Oculo-Renal Syndrome; Cerebellooculorenal
Syndrome 1; Cerebelloparenchymal Disorder 4; Classic Joubert Syndrome; Joubert-Bolthauser
Syndrome; Joubert Syndrome and Related Disorders; Joubert Syndrome Type A; JS; Pure
Joubert Syndrome
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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 JS 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:
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DETERMINATION
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LISTING
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REMARKS
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Meets
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111.07
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111.17
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112.05
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Equals
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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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