Search for subtelomeric imbalances by multiplex ligation-dependent probe amplification in Silver-Russell syndrome

Chromosomal aberrations are typically associated with primordial growth retardation, psychomotoric constrictions, and dysmorphisms. Since these features may be present in patients with Silver-Russell syndrome (SRS) and chromosomal disturbances are also detected in a subgroup of SRS patients, we screened a cohort of 45 SRS patients for cryptic subtelomeric imbalances. Submicroscopic deletions/duplications in the telomere regions are meanwhile well known to cause a broad spectrum of conspicuous phenotypes, characterized by mental retardation and multiple further congenital anomalies. We hypothesize that SRS might represent at the mild end of the broad phenotypic range of subtelomeric imbalances. Screening of the patients was performed by multiplex ligation-dependent probe amplification (MLPA), a technique that has already been shown to be effective and reliable for measuring copy numbers. We excluded pathogenetically relevant copy number variations in the subtelomeres in our SRS patient cohort, but one patient carried an apathogenic polymorphic Yq deletion. It can therefore be concluded that this type of chromosomal aberration does not belong to the genetic causes of SRS and it is not necessary to include this test in the diagnostic algorithm of the disease.