What are the other Names for this Condition? (Also known as/Synonyms)

• Cockayne Syndrome Type 2
• Cockayne Syndrome Type B

What is Cockayne Syndrome Type II? (Definition/Background Information)

• Cockayne Syndrome is a rare disorder which causes short stature, premature aging (progeria), severe photosensitivity, and moderate to severe learning delay
• This syndrome also includes failure to thrive in the newborn, very small head (microcephaly), and impaired nervous system development. Other symptoms may include hearing loss, tooth decay, vision problems, and bone abnormalities
• There are three subtypes according to the severity of the disorder and the onset of the symptoms:
  • Cockayne Syndrome Type 1 (type A), sometimes called “classic” or "moderate" Cockayne Syndrome, diagnosed during early childhood
  • Cockayne Syndrome Type 2 (type B), sometimes referred to as the “severe” or "early-onset" type, presenting with growth and developmental abnormalities at birth
  • Cockayne Syndrome Type 3 (type C), a milder form of the disorder 
• Cockayne Syndrome is caused by mutations in either the ERCC8 (CSA) or ERCC6 (CSB) genes. Inheritance is  autosomal recessive
• Cockayne Syndrome Type 2 is the most severe and affected people usually do not survive past childhood. Those with type 3 live into middle adulthood
• There is no cure yet. Treatment is supportive and may include educational programs for developmental delay, physical therapy, gastrostomy tube placement as needed; medications for spasticity and tremor as needed; use of sunscreens and sunglasses; treatment of hearing loss and cataracts; and other forms of treatment, as needed

(Source: Cockayne Syndrome Type II; Genetic and Rare Diseases Information Center (GARD) of National Center for Advancing Translational Sciences (NCATS), USA.)

Who gets Cockayne Syndrome Type II? (Age and Sex Distribution)

• Cockayne Syndrome Type II is a rare congenital disorder. The presentation of symptoms may occur at or following the birth of the child
• Both males and females may be affected
• Worldwide, individuals of all racial and ethnic groups may be affected

What are the Risk Factors for Cockayne Syndrome Type II? (Predisposing Factors)

• A positive family history may be an important risk factor, since Cockayne Syndrome Type II can be inherited
• Currently, no risk factors have been clearly identified for the disorder

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Cockayne Syndrome Type II? (Etiology)

• Inheritance of the condition is  autosomal recessive

(Source: Cockayne Syndrome Type II; Genetic and Rare Diseases Information Center (GARD) of National Center for Advancing Translational Sciences (NCATS), USA.)

Autosomal recessive: Autosomal recessive conditions are traits or disorders that occur when two copies of an abnormal gene have been inherited on a non-sex chromosome. If both parents have an autosomal recessive condition, there is a 100% likelihood of passing on the mutated genes to their children. If, however, only one mutant copy of the gene is inherited, the individual will be a carrier of the condition, but will not be present with any symptoms. Children born to two carriers, have a 25% chance of being homozygous dominant (unaffected), a 50% chance of being heterozygous (carrier), and a 25% chance of being homozygous recessive (affected).

What are the Signs and Symptoms of Cockayne Syndrome Type II?

The signs and symptoms of Cockayne Syndrome Type II may include:

• Abnormal auditory evoked potentials
• Abnormality of skin pigmentation
• Abnormality of the pinna
• Abnormality of visual evoked potentials
• Anhidrosis
• Ataxia
• Atypical scarring of skin
• Basal ganglia calcification
• Carious teeth
• Cataract
• Cerebral atrophy
• Cryptorchidism
• Cutaneous photosensitivity
• Decreased lacrimation
• Decreased nerve conduction velocity
• Delayed eruption of primary teeth
• Dementia
• Dental malocclusion
• Hepatomegaly
• Hypermetropia
• Hypertension
• Hypoplasia of teeth
• Hypoplastic iliac wing
• Hypoplastic pelvis
• Increased cellular sensitivity to UV light
• Intrauterine growth retardation
• Kyphosis
• Limitation of joint mobility
• Menstrual irregularities
• Micropenis
• Opacification of the corneal stroma
• Nystagmus
• Optic atrophy
• Patchy demyelination of subcortical white matter
• Peripheral dysmyelination
• Polyneuropathy
• Reduced subcutaneous adipose tissue
• Renal insufficiency
• Seizures
• Sensorineural hearing impairment
• Severe postnatal growth retardation
• Slender nose
• Sparse hair
• Square pelvis bone
• Tremor
• Thymic hormone decreased

(Source: Cockayne Syndrome Type II; Genetic and Rare Diseases Information Center (GARD) of National Center for Advancing Translational Sciences (NCATS), USA.)

How is Cockayne Syndrome Type II Diagnosed?

Cockayne Syndrome Type II is diagnosed on the basis of the following information:

• Complete physical examination
• Thorough medical history evaluation
• Assessment of signs and symptoms
• Laboratory tests
• Imaging studies
• Biopsy studies, if necessary

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Cockayne Syndrome Type II?

The complications of Cockayne Syndrome Type II may include:

• Hearing and vision loss
• Kidney dysfunction
• Walking difficulties

Complications may occur with or without treatment, and in some cases, due to treatment also.

How is Cockayne Syndrome Type II Treated?

There is no cure yet for Cockayne Syndrome Type II. Treatment is supportive and may include 

• Educational programs for developmental delay
• Physical therapy
• Gastrostomy tube placement as needed
• Medications for spasticity and tremor as needed
• Use of sunscreens and sunglasses
• Treatment of hearing loss and cataracts
• And, other forms of treatment, as needed

(Source: Cockayne Syndrome Type II; Genetic and Rare Diseases Information Center (GARD) of National Center for Advancing Translational Sciences (NCATS), USA.)

How can Cockayne Syndrome Type II be Prevented?

Currently, Cockayne Syndrome Type II may not be preventable, since it is a genetic disorder.

• Genetic testing of the expecting parents (and related family members) and prenatal diagnosis (molecular testing of the fetus during pregnancy) may help in understanding the risks better during pregnancy
• If there is a family history of the condition, then genetic counseling will help assess risks, before planning for a child
• Active research is currently being performed to explore the possibilities for treatment and prevention of inherited and acquired genetic disorders

Regular medical screening at periodic intervals with tests and physical examinations are recommended.

What is the Prognosis of Cockayne Syndrome Type II? (Outcomes/Resolutions) 

• The prognosis of Cockayne Syndrome Type II is dependent upon the severity of the signs and symptoms and associated complications, if any
• Individuals with mild conditions have better prognosis than those with severe symptoms and complications
• Typically, the prognosis is poor and most deaths occur during childhood

Additional and Relevant Useful Information for Cockayne Syndrome Type II:

The following DoveMed website link is a useful resource for additional information:

http://www.dovemed.com/diseases-conditions/rare-disorders/