Lack of infection with XMRV or other MLV-related viruses in blood, post-mortem brains and paternal gametes of autistic individuals

Background: Autistic spectrum disorder (ASD) is characterized by impaired language, communication and social skills, as
well as by repetitive and stereotypic patterns of behavior. Many autistic subjects display a dysregulation of the immune
system which is compatible with an unresolved viral infection with prenatal onset, potentially due to vertical viral
transmission. Recently, the xenotropic murine leukemia virus-related virus (XMRV) has been implicated in chronic fatigue
syndrome (CFS) and in prostate cancer by several, though not all studies.
Methodology/Principal Findings: We assessed whether XMRV or other murine leukemia virus (MLV)-related viruses
are involved in autistic disorder. Using nested PCR targeted to gag genomic sequences, we screened DNA samples from:
(i) peripheral blood of 102 ASD patients and 97 controls, (ii) post-mortem brain samples of 20 ASD patients and 17 sexand
age-matched controls, (iii) semen samples of 11 fathers of ASD children, 25 infertile individuals and 7 fertile controls.
No XMRV gag DNA sequences were detected, whereas peripheral blood samples of 3/97 (3.1%) controls were positive
for MLV.
Conclusions|Significance: No MLV-related virus was detected in blood, brain, and semen samples of ASD patients or
fathers. Hence infection with XMRV or other MLV-related viruses is unlikely to contribute to autism pathogenesis.