Partial monosomy 10p syndrome

A newborn infant with monosomy 10p13 is reported. The clinical signs and symptoms of the present case are compared with those of previously described cases. Although there is no pathognomonic feature, a characteristic monosomy 10p syndrome is recognizable.     

Prenatal diagnosis and molecular cytogenetic characterization of a de novo proximal interstitial deletion of chromosome 4p (4p15.2→p14)

We present prenatal diagnosis of de novo proximal interstitial deletion of chromosome 4p (4p15.2→p14) and molecular cytogenetic characterization of the deletion using uncultured amniocytes. We review the phenotypic abnormalities of previously reported patients with similar proximal interstitial 4p deletions, and we discuss the functions of the genes of RBPJ, CCKAR, STIM2, PCDH7 and ARAP2 that are deleted within this region.     

18q部分单体患儿的细胞和分子遗传学研究

临床发现1例智力低下伴轻度发育迟缓的女性患儿,对患儿进行G显带高分辨染色体核型分析, 发现18q21→qter缺失, 经多色荧光原位杂交和双色荧光原位杂交证实, 确定其核型为46,XX,del(18)(pter→q21:),ish del(18)(D18Z1+, qter-)。用DNA多态性方法分析, 该患儿从18q22.1至18qter区域内至少有8.7 Mbp丢失, 有MBP基因和GALNR基因缺失。缺失的18号染色体源自父亲。患者的智力低下和生长发育迟缓是18q21→qter缺失的结果, 或许与MBP基因和GALNR基因的缺失有关。     

Clinical and cytogenetic studies of two infants with partial monosomy G

Summary Clinical and cytogenetic studies are reported in two infants with a stable ring G chromosome. Identification of the abnormal chromosomes was performed by the G-banding and the Q-banding methods.     

Prenatal diagnosis of pure partial monosomy 18p associated with holoprosencephaly and congenital heart defects

We applied CMA to detect chromosomal variations during a prenatal diagnosis and detected a 4.5 Mb pure microdeletion at 18p11.3 that was not detected by conventional karyotyping. Fluorescent in situ hybridization (FISH) analysis was performed to confirm the deletion. Accurate breakpoints of the deletion in this patient were used to build correlations between monosomy 18p and the concomitant phenotypes, particularly holoprosencephaly (HPE), which is rarely reported in monosomy 18p11.3.     

Clinical and molecular cytogenetic analysis of a rare case of mosaicism for partial monosomy 3p and partial trisomy 10q in human

The results of comprehensive clinical examination and molecular cytogenetic analysis of a patient carrying chromosome 3p+ in 69% of the peripheral blood lymphocytes are presented. Using microdissection of the metaphase chromosomes followed by DOP-PCR, a DNA library specific for the abnormal chromosome was obtained. By fluorescence in situ hybridization (FISH) of this DNA library with chromosomes from the patient and a healthy donor, the aberrant chromosome was identified as der(3)t(3;10)(3p25;q24.3). Since this chromosome was present in only a proportion of patient's cells studied and no chromosome aberrations were revealed in cells of his parents, the der(3)t(3;10) is suggested to appear de novo. The cells carrying der(3)t(3;10) are monosomic for a proportion of 3p25 and trisomic for 10q24.3-->qter. The developmental malformations revealed in the patient, such as the specific features of facial skeleton, mental retardation, microcephaly, and others are similar to those described previously in patients with partial 3p monosomy and 10q trisomy.     

A case of partial 9p monosomy with some unusual clinical features.

A patient is described with a karyotype 46,XX,del(9)(qter leads to p22:) and having the main clinical characteristics of pure monosomy for part of the short arm of chromosome No 9, among which craniosynostosis and trigonocephaly. She has also a few atypical features: a clearly advanced osseous maturation, marked congenital vertebral anomalies and unusual dermatoglyphics.     

A rare case of monosomy 18p: translocation between chromosomes 18 and 21

A rare case of monosomy 18p with molecular cytogenetic characterization of 18;21 whole arm translocation is presented. An 8-year-old gril with mental deficiency and growth deficiency was the child of a 45-year-old healthy mother and 50-year-old nonconsanguineous father with unremarkable prenatal history. She had a round face, flat nasal bridge, micrognathia and hypotonia. Cytogenetic studies revealed de novo 45,XX,del(18)t(18;21) karyotype, which was confirmed by fluorescence in situ hybridization (FISH).     

Molecular and cytogenetic characterization of a de novo t(5p;21q) in a patient previously diagnosed as monosomy 21.

Genomic single-copy DNA fragments were used to characterize an undetected chromosome translocation in an individual whose metaphase chromosome analysis revealed apparent monosomy 21. Eight RFLPs detected by six probes were used to identify homologous sequences from chromosome 21 in DNA digests from the proband and her parents. These family studies showed that the proband was disomic for the distal region of 21q. Reverse banding and in situ hybridization of chromosome 21-specific probes to metaphase chromosomes from the proband revealed a de novo translocation with breakpoints at 5p13 or 14 and 21q11 or 21. In situ hybridization permitted orientation of the translocated portion of chromosome 21 on the derivative chromosome 5 and, in conjunction with molecular analysis and previous mapping studies, refined the physical map for the long arm of chromosome 21.     

A case of monosomy 21

A new case of monosomy 21 was observed in a newborn male. Characteristic clinical features include: an antimongoloid eye slants, large and low set ears, flat nose bridge, hypoplastic nipples, cardiac anomalies, muscular hypotonia, retarded psychomotor development. The karyotypes of the parents were normal.     

The use of foetal ovarian stromal cell culture for cytogenetic diagnosis. Stromal ovarian culture cytogenetic diagnosis

Some studies have been carried out to analyze human female first meiotic prophase. Most of them use samples from foetuses collected after legal interruption of pregnancy. In some cases, a control population is needed and foetuses aborted for non-chromosomal reasons are used. The assumption of these samples as being euploids could perhaps represent an error. In this article, we describe an easy methodology to certify the euploidy of foetal ovarian tissue using an one-week somatic culture. Using this protocol, we have obtained a primary culture in 88.2% of the studied cases, material usable for being karyotyped in 93.3% of the cases, and a cytogenetic diagnosis was performed in 100% of these cases. Finding the same karyotype in cultured cells in cases in which we had a prenatal cytogenetic diagnosis has validated the technique, and in applying this protocol we have been able to check our prophase meiotic-study control population.     

Partial monosomy 8p and partial trisomy 8p with moderate mental retardation.

A female patient with mosaicism for partial monosomy 8p and partial trisomy 8p is presented. Her karyotype is 46,XX, del(8)(p21)/46,XX, dup(8)(p21----pter). She showed minimal dysmorphic features, agenesis of the corpus callosum and moderate developmental delay. There is no previous report of mosaicism for partial monosomy and partial trisomy 8p. The clinical findings in the presently described patient are less severe than those reported in cases with only monosomy or trisomy of the distal part of chromosome 8.     

Phenotypic and cytogenetic spectrum of 9p trisomy

Trisomy 9p is one of the most frequent autosomal anomalies compatible with long survival rate. The spectrum of clinical severity in trisomy 9 roughly correlates with the extent of trisomic chromosome material. Trisomy 9p is a clinically well delineated syndrome and of all stigmata craniofacial dysmorphism is most specific. In this study we report five cases with de novo trisomy 9p. The study aimed at the identification of the genotype/phenotype correlations in patients with different breakpoints. GTG banding, DAPI stain, whole chromosome paint, centromere, telomere and 9p21 specific locus probes demonstrated that partial trisomy 9p in case 1 was due to isochromosome 9p with translocation of the long arm of re-arranged chromosome 9 onto the short arm of chromosome 13, cases 2 and 3 had intrachromosomal duplication of the short arm of chromosome 9 [dup(9)(p21p24)], case 4 had "classical" 9p trisomy and case 5 had duplication of whole short arm and part of the long arm of chromosome 9 (partial 9 trisomy). Although cases 1 to 4 had trisomy involving 9p, cases 1 and 2 exhibited the classical clinical manifestations of 9p trisomy, while cases 3 and 4 had additional features overlapping with Coffin-Siris syndrome. The present study strengthens the association of Coffin-Siris syndrome and 9p, the significance of such observations may point to possible gene location of Coffin-Siris syndrome on 9p. Case 5 had additional manifestations more than those typical of trisomy 9p which could be due to duplication of 9q21 region. Wide gap between 1st and 2nd toes, observed in the studied cases, can be added to the phenotype of this trisomy. Three of our cases had brain malformations, case 3 had dilated ventricles with hypogenesis of corpus callosum, case 4 had agenesis of corpus callosum, and case 5 had Dandy-Walker malformation. We also suggest that dosage effects of genes located in 9pter-q22 contribute to the etiology of Dandy-Walker syndrome. We recommend MRI studies as a routine in all cases with trisomy 9p.     

A cytogenetic ladder-map of the wheat homoeologous group-4 chromosomes

We report the results of chromosome maps of wheat homoeologous chromosomes 4A, 4B, and 4D using 40 RFLP markers and 39 homozygous deletion lines. Deletion breakpoints divide the chromosomes into 45 subarm intervals with 32 intervals distinguished by molecular markers. The chromosome maps confirm the homoeology of arms 4AS to 4BL and 4DL, and 4AL to 4BS and 4DS. The chromosome map of 4A reveals novel information concerning the 4AL-5AL-7BS cyclical translocation. The presence of homoeologous group-4 long-arm markers, Xksu G10 and Xpsr 1051, intervening between the translocated 5AL and 7BS chromosome segments in 4AL suggests that the translocation events are more complex than was earlier believed. Chromosome maps confirm a pericentric inversion in Chinese Spring chromosome 4B. The consensus chromosome map is compared to the genetic map of wheat to construct a cytogenetic ladder-map (CLM). The CLM reveals an unequal distribution of recombination along the length of the chromosome arms. Recombination is highest in the distal half, and low in the proximal half, of the chromosome arms.     

The dermatoglyphic and clinical features of the 9p trisomy and partial 9p monosomy syndromes

Summary The physical and dermatoglyphic features obtained from published reports of 128 patients with the trisomy 9p syndrome and 27 patients with the partial 9p monosomy syndrome are tabulated. This information is also provided on two new individuals with each of these chromosomal disorders. The dermal ridge patterns and palmar creases of trisomy 9p which are most helpful from a diagnostic standpoint are zygodactylous or absent palmar digital triradii, brachymesophalangy, reduced total finger ridge count, complex thenar/ID I patterns, transverse palmar ridge alignment, simian creases, distal axial triradii, and great toe and hallucal arch patterns. The characteristic features in partial 9p monosomy include dolichomesophalangy with accessory finger flexion creases, digital whorl patterns and elevated total finger ridge count, distal axial triradii, simian creases, and palmar dermal ridge dissociation.     

Double autosomal chromosomal aberration (3p trisomy/9p monosomy) and sex-reversal

A 26-year-old girl with multiple congenital malformations, sex-reversal, and partial trisomy 3p/monosomy 9p is described. A possible influence of autosome aberrations on sexual differentiation is discussed.