title: Prenatal Screening of 21 Microdeletion/Microduplication Syndromes and Subtelomeric Imbalances by MLPA in Fetuses with Increased Nuchal Translucency and Normal Karyotype.
abstract: Fetuses with increased nuchal translucency thickness (NT) are at increased risk for chromosomal abnormalities. In case of a normal karyotype, a minority of them may present with structural abnormalities or genetic syndromes, which may be related to submicroscopic chromosomal imbalances. The objective of this study was to evaluate whether MLPA screening of 21 syndromic and subtelomeric regions could improve the detection rate of small chromosomal aberrations in fetuses with increased NT and a normal karyotype. A total of 106 prenatal samples from fetuses with NT ≥ 99th centile and normal R- and G-banding were analyzed by MLPA for subtelomeric imbalances (SALSA P036 and P070) and 21 syndromic regions (SALSA P245). One sample showed a benign CNV (dup(8)pter, FBXO25 gene), and 1 patient was found to have a loss of 18 qter and a gain of 5 pter as a result of an unbalanced translocation. The incidence of cryptic pathogenic variants was <1% or 2.7% when only fetuses with other ultrasound abnormalities were taken into account. Submicroscopic imbalances in fetuses with increased NT may be individually rare, and genome-wide screening seems more likely to improve the diagnostic yield in these fetuses.
authors.affiliation: Service de Cytogx00E9;nx00E9;tique Mx00E9;dicale, Unitx00E9; de Mx00E9;decine Fx0153;tale, CHU Clermont-Ferrand, Clermont-Ferrand, France.
authors.forename: Laetitia
authors.initials: L
authors.lastname: Gouas
authors.forename: Stéphan
authors.initials: S
authors.lastname: Kémény
authors.forename: Anne-Marie
authors.initials: AM
authors.lastname: Beaufrère
authors.forename: Eléonore
authors.initials: E
authors.lastname: Eymard-Pierre
authors.forename: Céline
authors.initials: C
authors.lastname: Pebrel-Richard
authors.forename: Andrei
authors.initials: A
authors.lastname: Tchirkov
authors.forename: Didier
authors.initials: D
authors.lastname: Lemery
authors.forename: Hélène
authors.initials: H
authors.lastname: Laurichesse-Delmas
authors.forename: Philippe
authors.initials: P
authors.lastname: Vago
authors.forename: Carole
authors.initials: C
authors.lastname: Goumy
mesh_terms: D000293:Adolescent; D000328:Adult; D002872:Chromosome Deletion; D025063:Chromosome Disorders / Q000000981:diagnostic imaging* / Q000235:genetics; D058674:Chromosome Duplication; D056915:DNA Copy Number Variations; D015342:DNA Probes / Q000235:genetics; D005260:Female; D006801:Humans; D059785:Karyotype; D025202:Molecular Diagnostic Techniques; D048208:Nuchal Translucency Measurement; D021141:Nucleic Acid Amplification Techniques; D055815:Young Adult
chemical_list: D015342:DNA Probes