Partial 18q trisomy and 18p monosomy resulting from a maternal pericentric inversion, inv(18)(p11.2q21.3)

Abstract

SummaryA 7-year-old boy with dysmorphic features was found to have a recombinant chromosome 18, rec(18), resulting from meiotic recombination of a maternal pericentric inversion, inv(18) (pll.2q21.3), as defined by high-resolution banding. He was trisomic for the long arm (q21.3-qter) and monosomic for the short arm (pl 1.2-pter) of chromosome t8. His clinical features were compared with those in other rec(18) cases, and also those in monosomy 18p, trisomy 18qter and full trisomy 18 syndromes. The risk of recombinant formation for inv(18) carriers was also discussed.

A boy with partial dup(18q)/del(18p) due to a maternal pericentric inversion: Genotype–phenotype correlation and risk of recombinant chromosomes based on systematic review of the literature

“…The region duplicated in the case herein reported harbors the distal critical region. However, our proband and some reported cases in the literature do not have a phenotype compatible with that of the Edwards syndrome [Vianna‐Morgante et al, ; Kukolich et al, ; Andrews et al, ; Asano et al, ; Ayukawa et al, ; Mejia‐Baltodano et al, ; Prontera et al, ; Kariminejad et al, ].…”

“…). We selected 18 references for full text assessment, from which 13 studies met our inclusion criteria: [Vianna‐Morgante et al, ; Kukolich et al, ; Teyssier and Bajolle, ; Asano et al, ; Ayukawa et al, ; Israels et al, ; Mejia‐Baltodano et al, ; Leonard et al, ; Roberts et al, ; Vermeulen et al, ; Prontera et al, ; Kariminejad et al, ; Zamani et al, ]. Additionally, four articles were included by manual search [Jacobs et al, ; Turleau and de Grouchy, ; Vigi et al, ; Andrews et al, ].…”

“…The combination of partial trisomy 18q—dup(18q)—and partial monosomy 18p—del(18p)—is rare. To date, only 19 cases resulting from recombination of parental pericentric inversions have been reported [Vianna‐Morgante et al, ; Turleau and de Grouchy, ; Kukolich et al, ; Andrews et al, ; Asano et al, ; Ayukawa et al, ; Israels et al, ; Mejia‐Baltodano et al, ; Leonard et al, ; Roberts et al, ; Vermeulen et al, ; Prontera et al, ; Kariminejad et al, ; Zamani et al, ]. The phenotype of patients carrying a recombinant chromosome 18 with dup(18q) is a mixture of clinical features typical of del(18p) and dup(18q) karyotypes, including developmental delay, intellectual disability of various degrees, facial dysmorphisms, and hand and feet anomalies [Israels et al, ].…”

Novel case of paternal paracentric inversion causing partial trisomy 13 and review of the literature

“…One method by which this may occur is by replication of a chromosome with an inversion. An inversion is a segment of a chromosome which has been detached, rotated 180° lengthwise, and re‐attached (Asano, Ikeuchi, Shinohara, Enokido, & Hashimoto, ). Inversions may be further classified into categories based on the location of the inversion, either pericentric or paracentric.…”

Pericentric inversion of chromosome 18 in parents leading to a phenotypically normal child with segmental uniparental disomy 18

“…Most of these patients had severe mental retardation and multiple congenital anomalies with severe morbidity and often early lethal outcome. [6][7][8][9][10][11][12][13][14][15][16][17] There are a few reports of patients with recombinant dup(18q)/ del(18p) resulting from inversions, with very mild phenotypic findings and behavioral problems. 18,19 The first offspring of the family described in this study is a further case of dup(18q)/del(18p), with very mild dysmorphic features and normal developmental and borderline mental ability.…”