AP1B1

Clinical Characteristics

The clinical features of KIDAR include:

Skin changes

  • Dry, scaly, thickened skin
  • Generalized reddening of the skin
  • Thickened skin over the palms and soles
  • Sparse hair, with or without a wiry texture
  • Thick yellow scales on scalp
  • Sparse or absent eyebrows
  • Excessive creases over palms and soles (in some individuals)
  • Excessive sweating (reported in 1 patient)

Liver problems (in some patients)

  • Liver disease(s), which may include abnormal liver function detected on laboratory tests

Gut-related problems (in some individuals)

  • Intestinal problem(s), which may include diarrhea
  • Faltering growth (weight or rate of weight gain that is much lower than that of other children of similar age)

Neurological problems

  • Global developmental delay (delay in all areas of development, including motor, speech, cognitive, and social)
  • Intellectual disability
  • Over-responsive deep tendon reflexes (DTR) on neurological examination (in some patients)
  • Hearing loss
  • Light sensitivity (in some individuals)
  • Structural brain abnormalities detected on magnetic resonance imaging (MRI) (in some individuals):
    • Atrophy of the cerebral cortex (the outermost layer of the brain responsible for thinking and processing information form the five senses)
    • Thin corpus callosum, the C-shaped bundle of nerves found under the cerebral cortex of the brain that allows communication between the two hemispheres of the brain

Facial differences (variable, mild; in some individuals)

  • Prominent, protruding forehead
  • Hairline recession
  • Outward turning of the eyelid

The following features were observed in a case report of an adult patient with KIDAR:

  • Scarring of the cornea of the eye
  • Recession of the gingiva
  • Fissured tongue
  • Tooth loss and poor calcification of teeth

Analyzing the blood of the patient in the laboratory may reveal the following changes:

  • Low serum copper
  • Low ceruloplasmin levels
  • Low plasma zinc
  • Elevated very-long-chain fatty acids (in some individuals)
  • Altered liver function tests (liver profile) (in some individuals):
    • High alanine aminotransferase
    • High gamma-glutamyl transferase
    • High alkaline phosphatase
    • High bile acids
    • Low plasma albumin
  • Complete or full blood count (FBC or CBC) may show changes (in some individuals):
    • Low platelets (episodic or persistent)
    • Anemia