Current Molecular Medicine - Volume 2, Issue 5, 2002

Patients with pycnodysostosis, a rare skeletal dysplasia, present with bone abnormalities such as short stature, acroosteolysis of distal phalanges, and skull deformities. The disease is caused by a deficiency of the cysteine protease cathepsin K which is responsible for degradation of collagen type I and other bone proteins. Osteoclasts, bone cells of hematopoietic origin responsible for bone mineral as well as protein matrix de Read More

Infantile and classical late infantile neuronal ceroid lipofuscinoses (NCL) are two recent additions to the expanding spectrum of lysosomal storage disorders caused by deficiencies in lysosomal hydrolases. They are latecomers to the lysosomal storage disorders, probably because of the heterogeneous nature of the storage material, which precluded meaningful biochemical analysis. Infantile NCL is caused by deficiency i Read More

Positional cloning efforts of genes mutated in Batten disease and in the Finnish type of variant late infantile neuronal ceroid lipofuscinosis resulted in the identification of two novel genes, CLN3 and CLN5, and corresponding gene products that proved to be residents of lysosomes. Although the clinical phenotype of these NCL subtypes differs in the age of onset, average life span and EEG findings, the major component of materi Read More

Mucolipidosis Type IV (MLIV) is a lysosomal storage disorder that is characterized by severe neurologic and ophthalmologic abnormalities. It is a progressive disease that usually presents during the first year of life with mental retardation, corneal opacities, and delayed motor milestones. First described in 1974, MLIV is a rare autosomal recessive disease and the majority of patients diagnosed to date are of Ashkenazi Jewish de Read More

Hermansky-Pudlak syndrome (HPS) has evolved into a group of genetically distinct disorders characterized by oculocutaneous albinism, a storage pool deficiency, and impaired formation or trafficking of intracellular vesicles. HPS-1 results from mutations in the HPS1 gene and affects approximately 400 individuals in northwest Puerto Rico due to a 16-bp duplication in exon 15. Another 13 mutations have been reported Read More

Chediak Higashi syndrome (CHS) is a rare, autosomal recessive disorder that affects multiple systems of the body. Patients with CHS exhibit hypopigmentation of the skin, eyes and hair, prolonged bleeding times, easy bruisability, recurrent infections, abnormal NK cell function and peripheral neuropathy. Morbidity results from patients succumbing to frequent bacterial infections or to an “accelerated phase” lympho Read More

A small number of inherited diseases show a combination of immunological and pigmentation defects. Chediak-Higashi, Griscellis and Hermansky-Pudlak syndromes are all autosomal recessive diseases with these characteristics. Recent advances in both the identification of the genes giving rise to these diseases and the cell biology of immune cells and melanocytes have begun to reveal the molecular links between immunod Read More

To maintain proper cellular function, the amount and distribution of cholesterol residing within cellular membranes must be regulated. The principal disorder affecting transport of cholesterol through the late endosomal / lysosomal system and intracellular cholesterol homeostasis is Niemann- Pick type C (NPC) disease. The genes responsible for NPC disease have been identified, and the encoded Niemann-Pick C1 (NPC1) and Ni Read More