Familial pericentric inversion (10) and its effect on two offspring

Molecular cytogenetic analysis of partial monosomy 10p and trisomy 10q resulting from familial pericentric inversion (10): a first case report in Chinese population

Background

Chromosome aberrations of 10p monosomy and 10q trisomy resulting from parental pericentric inversion 10 are extremely rare, and to date, very few reports have been published on the matter.

Case Presentation

A 30-year-old pregnant woman with recurrent pregnancy loss is enrolled in this research. In this pregnancy, spontaneous abortion occurred in the first trimester of her pregnancy. Chromosomal microarray analysis of the abortion tissue showed a partial 10p monosomy (arr[GRCh37] 10p15.3p11.21(100,047_34,848,853) × 1) and a duplication of 10q (arr[GRCh37] 10q26.13q26.3(126,093,990_135,426,386) × 3). Further parental karyotype analysis indicated that the chromosomal abnormalities in the fetus was resulted from paternal pericenric inversion inv(10)(p11.21q26.13). This study presents the first case of a large deletion of 10p combined with 10q trisomy, resulting in pregnancy loss. Of these two manifestations, the large deletion of chromosome 10p may be the primary reason for spontaneous abortion in this subject.

Conclusions

This study presents the first case of partial 10p monosomy associated with 10q trisomy in Chinese population. It provides more information on the chromosome aberration of 10p monosomy and 10q trisomy and further strengthens the application value of microarray in the molecular etiological diagnosis of recurrent spontaneous abortion.

Fertility problems in males carrying an inversion of chromosome 10

Chromosomal inversion is closely related to male infertility. Inversion carriers may produce abnormal gametes, which may lead to partial duplication/deletion of the embryonic chromosome and result in spontaneous abortion, a fetus with multiple anomalies, or birth of a malformed child. Genetic counselling remains challenging for these carriers in clinical practice. We report two male carriers with inversion of chromosome 10 and review 26 reported cases. In the first case, 46,XX,inv(10)(p13q22) of the fetal chromosome was found in prenatal diagnosis; this was inherited from the paternal side with 46XY,inv(10)(p13q22). Another case was a male carrier with inv(10)(q21.2q22.1). There have been 25 (89.3%) cases of pericentric inversion and three (10.7%) cases of paracentric inversion involving chromosome 10. Of 28 cases, nine were associated with pregestational infertility of the couples, while the other 19 cases were associated with gestational infertility of the couples or normozoospermia. The breakpoints at 10p15, 10p11, 10q11, and 10q21 were associated with pregestational infertility of the couples. The breakpoints at 10p15, 10p14, 10p13, 10p12, 10p11, 10q11, 10q21, 10q22, 10q23, 10q24, 10q25, and 10q26 were related to gestational infertility of the couples or normozoospermia. Although there is a high risk of infertility or recurrent miscarriages, carriers with inversion of chromosome 10 might produce healthy offspring. Natural pregnancy can be used as a choice for inversion carriers with recurrent spontaneous abortion.

Prenatal diagnosis and molecular cytogenetic characterization of rec(10)dup(10p)inv(10)(p11.2q26.3) in a fetus associated with paternal pericentric inversion

OBJECTIVE

We present prenatal diagnosis and molecular cytogenetic characterization of a recombinant chromosome 10 in a fetus associated with a paternal pericentric inversion.

CASE REPORT

A 35-year-old woman underwent amniocentesis at 18 weeks of gestation because of an advanced maternal age. Amniocentesis revealed a karyotype of 46,XY,der(10)del(10) (q26.3)dup(10)(p11.2p15). She underwent repeat amniocentesis at 21 weeks of gestation and array comparative genomic hybridization revealed a 31.65-Mb duplication of chromosome 10p15.3-p11.22 and a 3.07-Mb deletion of chromosome 10q26.3. Prenatal ultrasound findings were unremarkable. She was referred for genetic counseling and cytogenetic analysis revealed a karyotype of 46,XY,inv(10)(p11.2q26.3) in the father and a karyotype of 46,XX in the mother. The pregnancy was subsequently terminated, and a fetus was delivered with prominent facial dysmorphism. Postnatal cytogenetic analysis of the placenta revealed a karyotype of 46,XY, rec(10)dup(10p)inv(10)(p11.2q26.3). Fluorescence in situ hybridization analysis revealed a duplication of terminal 10p and a deletion of terminal 10q in the recombinant chromosome 10. Array comparative genomic hybridization analysis of the cord blood and umbilical cord confirmed the prenatal diagnosis.

CONCLUSION

Prenatal diagnosis of a recombinant chromosome because of an advanced maternal age should alert the possibility of a paternal pericentric inversion.

Relatives with opposite chromosome constitutions, rec(10)dup(10p)inv(10)(p15.1q26.12) and rec(10)dup(10q)inv(10)(p15.1q26.12), due to a familial pericentric inversion

Large pericentric inversions in chromosome 10 are rare chromosomal aberrations with only few cases of familial inheritance. Such chromosomal rearrangements may lead to production of unbalanced gametes. As a result of a recombination event in the inversion loop, 2 recombinants with duplicated and deficient chromosome segments, including the regions distal to the inversion, may be produced. We report on 2 relatives in a family with opposite terminal chromosomal rearrangements of chromosome 10, i.e. rec(10)dup(10p)inv(10) and rec(10)dup(10q)inv(10), due to familial pericentric inversion inv(10)(p15.1q26.12). Based on array-CGH results, we characterized the exact genomic regions involved and compared the clinical features of both patients with previous reports on similar pericentric inversions and regional differences within 10p and 10q. The fact that both products of recombination are viable indicates a potentially high recurrence risk of unbalanced offspring. This report of unbalanced rearrangements in chromosome 10 in 2 generations confirms the importance of screening for terminal imbalances in patients with idiopathic intellectual disability by molecular cytogenetic techniques such as FISH, MLPA or microarrays. It also underlines the necessity for FISH to define structural characteristics of such cryptic intrachromosomal rearrangements and the underlying cytogenetic mechanisms.

Case report of rec(7)dup(7q)inv(7)(p22q22) and a review of the recombinants resulting from parental pericentric inversions on any chromosomes

We report a rare case of duplication for 7q22 --> 7qter and deletion for 7p22 --> 7pter, resulting from a meiotic recombination of a paternal pericentric inversion, inv(7)(p22q22). The newborn boy had the 7q trisomy syndrome. In addition, the diagnosis of chondrodysplasia punctata was made from lumbar and hand X-ray films taken soon after birth. Only two cases of rec(7)dup(7q), both in a single family, have been reported previously. We review 133 offspring with recombinations resulting from pericentric inversions on any chromosomes reported between 1981 and 1995. Of the 133 cases, 110 had a long-arm duplication and short-arm deletion, while only 23 had a short-arm duplication and long-arm deletion. In 85 of the 133 cases, the mother was an inversion carrier (five carriers had two affected offspring), and in 46, the carrier was a father (one carrier had three affected offspring). Kaiser [Hum Genet 1984;68:1-47] reviewed 63 offspring with recombinations derived from a parental pericentric inversion reported between 1972 and 1981. In both surveys, recombinations resulting from pericentric inversions of chromosomes 1, 12, 19, and Y were not found.

A complex chromosome translocation resulting in deletion 11p and associated with uveal colobomata

A boy with a complex chromosome rearrangement of chromosomes 3, 10, and 11 resulting in a deletion of the short arm of chromosome II is presented. The occurrence of uveal coloboma as an isolated congenital malformation might suggest a chromosomal site for this ocular anomaly in proximity to the aniridia locus.

Familial 10p trisomy resulting from a maternal pericentric inversion

We report a familial recombination of a pericentric inversion of chromosome 10 resulting in 2 affected relatives who had 10p trisomy and 10q monosomy with the karyotypic abnormality designated rec(10) dup p,inv(10) (p11.2q26). Both of these individuals had the typical characteristics of 10p trisomy, however, at birth the proposita had mild facial anomalies suggesting that the distinct facial characteristics may be of postnatal onset in some cases. In addition, the proposita had gastroesophageal reflux causing severe anemia. The phenotype of our patients is compared to 41 patients with 10p trisomy reported in the literature.

Trisomy 10p syndrome owing to maternal pericentric inversion

A female infant with karyotype 46,XX,rec(10),dup p inv(10)(p11.2q25.2)mat is presented. She had both duplication of 10p and deletion of distal 10q, but only had the constellation of specific features characteristic of duplication of 10p.

A case of two inversion (10) recombinants in a family

A family is described in which the mother's four pregnancies resulted in one spontaneous abortion, one healthy boy, and a male and female sib with developmental delay and multiple minor dysmorphic features. Chromosome analysis showed a large pericentric inversion of chromosome 10, involving the region between bands p15.1 and q25.2, in the father and the healthy son: 46,XY,inv(10) (p15.1q25.2), and an unbalanced karyotype in the two affected sibs: rec(10),dup p,inv(10) (p15.1q25.2). The unbalanced chromosome has been produced by meiotic recombination between the inversion chromosome and its normal homologue. The two affected sibs have partial duplication of 10p and partial deficiency of 10q, and share a large number of clinical features, several of which have previously been described in both of these chromosome imbalances. We believe this to be the largest pericentric inversion of chromosome 10 reported to have produced recombinant offspring.

Proximal duplication of the long arm of chromosome 10 (10q11.2----10q22): a distinct clinical entity

This report summarizes the clinical and cytogenetic findings in a 16-year-old moderately mentally retarded girl with 10q11.2----10q22 duplication. The phenotypic findings are identical to those found in one other patient with the same autosomal duplication. These data suggest that proximal 10q11.2-10q22 duplication is associated with a specific clinically recognizable syndrome.

Coloboma and microphthalmos in chromosomal aberrations. Chromosomal aberrations and neural crest cell developmental field

A survey of more than 500 reports on patients with autosomal chromosomal aberrations associated with microphthalmos and/or coloboma shows that these anomalies are unspecific. Anterior chamber anomalies were common as were abnormal ears, preauricular pits and tags, cleft lip-palate, micrognathia, urogenital malformations, congenital heart disease, atresia of the anus and minor malformations of the hands and feet. It is proposed that the chromosomal aberrations induce faulty development of neural crest cells and rostral neural plate derivatives.