ABSTRACT
Chediak-Higashi syndrome (CHS) is a rare autosomal recessive disorder in which an immune deficiency occurs in association with pigmentation abnormalities. Most patients who do not undergo bone marrow transplantation die of a lymphoproliferative syndrome, though some patients with CHS have a relatively milder clinical course of the disease. The large size of the LYST gene, defective in CHS, has made it difficult to screen for mutations in a large number of patients. Only 8 mutations have been identified so far, and all lead to a truncated LYST protein. We conducted protein truncation tests on this gene in 8 patients with CHS. Different LYST mutations were identified in all subjects through this approach, strengthening the observation of a high frequency of truncated LYST proteins as the genetic cause of CHS.
Subject(s)
Chediak-Higashi Syndrome/genetics , Proteins/genetics , Terminator Regions, Genetic , Adolescent , Adult , Chediak-Higashi Syndrome/complications , Chediak-Higashi Syndrome/metabolism , Child , Child, Preschool , Codon/genetics , Epstein-Barr Virus Infections/complications , Female , Humans , Infant , Lymphoproliferative Disorders/etiology , Lysosomes/metabolism , Male , Proteins/chemistry , RNA, Messenger/genetics , Reverse Transcriptase Polymerase Chain Reaction , Sequence Deletion , Vesicular Transport ProteinsABSTRACT
A prospective study was carried out among 190 low birthweight neonates (less than 2,500 g) in order to assess their ratio of total body fat by 2 adiposity indices: Weight/Height3 (W/H3) at birth and Weight/Height2 (W/H2) subsequently. Adequate for gestational age (AGA) girls with weight indices (W/H3) above the 10th percentile (AGA/I+) had a lower height than AGA/I- girls on the 6th (p less than 0.01) and 9th (p less than 0.05) months of corrected chronological ages. Mean weight and height of small for gestational age (SGA) neonates with weight indices (W/H3) lower than the 10th percentile (SGA/I-) were similar to the SGA/I+ as soon as 3 months of corrected chronological age. SGA/I+ infants experienced a progressive increase in low weight indices (W/H2) until 15-18 months without significant differences with SGA/I- at 3, 6, 9 months of corrected chronological age. Meanwhile, low indices (W/H2) were more frequently observed in SGA/I- at 15-18 months. Thus the early characteristics in weight indices disclose a lower ratio of body fat in SGA infants than in normal children, at least up to age 15-18 months.