Krabbe disease (KD) (also known as globoid cell leukodystrophy or galactosylceramide lipidosis) is a rare and often fatal lysosomal storage disease that results in progressive damage to the nervous system. KD involves dysfunctional metabolism of sphingolipids and is inherited in an autosomal recessive pattern. The disease is named after the Danish neurologist Knud Krabbe (1885–1961). Signs and symptoms
Symptoms in asymptomatic infantile-onset (<12 months after birth) and later-onset Krabbe disease present themselves differently. Of individuals with infantile-onset Krabbe disease, 85–90% display progressive neurologic deterioration in infancy and death before the age of two. Symptoms include irritability, fevers, limb stiffness, seizures, feeding difficulties (like GERD), vomiting, staring episodes, and slowing of mental and motor development. In the first stages of the disease, doctors often mistake the symptoms for those of cerebral palsy. Other symptoms include muscle weakness, spasticity, deafness, optic atrophy, optic nerve enlargement, blindness, paralysis, and difficulty when swallowing. Prolonged weight loss may also occur.10–15% of individuals with later-onset Krabbe disease have a much slower disease progression. These individuals may also display symptoms such as esotropia, slurred speech, and slow development or loss of motor milestones. Causes
Krabbe disease is caused by mutations in the GALC gene located on chromosome 14 (14q31), which is inherited in an autosomal recessive manner. Mutations in the GALC gene cause a deficiency of an enzyme called galactosylceramidase.
The transverse nasal crease or groove is a usually white line between the upper two-thirds and the lower third of the human nose (slightly above the cartilage tip between the bridge and nostrils). It can occur as the result of heredity, accident, or the constant rubbing or wiping of the nose, commonly referred to as the allergic salute. Occurrence
In addition to cases caused by heredity, physical injury, the transverse nasal crease is common in children and adults with chronic nasal allergies. People with allergies often use their hands to remove mucus from a runny nose or rub an itchy nose. As the hand slides upward, the tip of the nose is pressed up, thus creating the crease. Appearance
The appearance of the line depends on skin pigmentation. On lighter-skinned people, the transverse nasal crease is lighter in color than the surrounding skin, and may appear white. This is due to hypopigmentation resulting from the low level of melanin present in the damaged skin. In darker-skinned people, the line may appear darker than the surrounding skin. == References ==