[Hyper-IgM syndrome in members of two unrelated Chilean families: molecular and mutation analysis].
BACKGROUND
Hyper-IgM syndronie (HIGM) is a rare primary immunodeficiency used to describe a heterogeneous group of disorders characterized by recurrey bacterial infrctions, normal or elevated serum IgM levels and low or absent serum IgG, IgA and IgE.


OBJECTIVE
To make definitive diagnosis, detect mutations in carriers and perform genetic counseling in patients with HIGM.


METHODS
We studied the expression of CD40L, CD40 and made a mutation analysis of the CD40L gene in 3 males of 2 unrelated Chilean families diagnosed as a possible syndrome of hyper-IgM and 3 relatives.


RESULTS
We identified a deletion frameshift in the exon 2 (delA225) of the extracellular domain of GD40L gene in one patient and verified the carrier stains of his mother and sister. The other patients showed a low expression of GD40L in activated T cells (65.3% ammd 65.5%) and a normal expressiomi of CD40. No alterations were found in the single strand conformation polymorphism analysis of the CD40L.


CONCLUSIONS
These result allowed us to make a definite diagnosis of HIGM1 of a patient, detect female carriers and suggest a HIGM of recessive inheritance with normal CD40 expression in the patients of the second family.
Luttges
Pamela D
PD
Laboratorio de Inmunología, Facultad de Medicina, Universidad de Valparaíso. pamela.luttges@uv.cl
Retamal
David F
DF
Spencer
Michael Y
MY
Carrión
Flavio A
FA
Valenzuela
Viviana M
VM
Navarro
Sara V
SV
De Cornejo
Mónica L
ML
D023201:CD40 Ligand / Q000097:blood / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D002677:Chile; D005260:Female; D016368:Frameshift Mutation / Q000235:genetics*; D005817:Genetic Counseling; D006801:Humans; D006942:Hypergammaglobulinemia / Q000175:diagnosis / Q000235:genetics*; D007075:Immunoglobulin M / Q000097:blood / Q000235:genetics*; D007223:Infant; D008297:Male; D013577:Syndrome; D048008:TNF Receptor-Associated Factor 3; D047988:Tumor Necrosis Factor Receptor-Associated Peptides and Proteins / Q000097:blood / Q000235:genetics*
D007075:Immunoglobulin M; D048008:TNF Receptor-Associated Factor 3; C090656:TRAF3 protein, human; D047988:Tumor Necrosis Factor Receptor-Associated Peptides and Proteins; D023201:CD40 Ligand