Objective       To study the clinical features of Chediak-Higashi syndrome (CHS) and lysosomal trafficking regulator (LYST) gene mutations in 4 patients.      Methods       Clinical and laboratory data about 4 female CHS children were analyzed. DNA and RNA were isolated from peripheral blood of the children and their parents. Pathogenic gene LYST was analyzed by DNA-PCR/RT-PCR and direct sequencing. Corresponding mutation points in the parents were amplified by PCR and sequenced to determine LYST gene mutation carriers according the mutation points in the children.      Results       The 4 CHS children were females with an average age of 38  months. All of them presented with hypopigmentation accompanying nystagmus. Their melanin was decreased in hair and its distribution was characterized by little spots under microscope. Fever occurred in patients 1-3 with decreased blood cell line 2 and nucleated gigantic inclusion bodies in bone marrow cells

thus CHS was diagnosed. The LYST gene mutations were found at c.3113CT

Q980X and c.6788AT

K2205X in patient 1

at c.5327CT

R1718X and c.608CT

R145X in patient 2

and at c.5411-5414 del TTTC

L1741fsX1758 and c.7975 CT

R2596X in patients 3. The 6 mutations were novel mutations and 8 LYST gene mutation carriers were identified. No LYST gene mutation was found in patient 4.      Conclusion       CHS is characterized by hypopigmentation

nystagmus

decreased hair melanin in hair with its distribution characterized by small spots

and nucleated gigantic inclusion bodies in bone marrow cells. Six novel LYST gene mutations have been found by LYST gene analysis.