Trisomy 8 mosaicism syndrome. Report of monozygotic twins

An unusual case of trisomy 8 mosaicism complicated by coexistence of phenylketonuria

Trisomy 8 syndrome, also known as " Warkany syndrome type 2 ", was first reported in 1971. Complete trisomy 8 are mostly aborted spontaneouslyinthe first trimester. Trisomy 8 mosaicism (T8M), predominated in the current cases reported. Itisahighlyheterogeneous Chromosome disorder. We know little about its effects on fertility. In this case, a patient with T8M combined with phenylketonuria was diagnosed. She's mentally retarded. After evaluating the anatomy and function of the reproductive system, the patient conceived through preimplantationgenetictesting-intracytoplasmicsperminjection-embryotransfer (PGT-ICSI-ET) and obtained a healthy fetus, which is the first report. The study focuses on the maintenance of fertility in patients with T8M, the effects of phenylketonuria and genetic counseling.

San Luis Valley recombinant chromosome 8 and tetralogy of Fallot: a review of chromosome 8 anomalies and congenital heart disease

Tetralogy of Fallot, the most common cyanotic heart defect, has not been closely associated with a specific chromosome defect. The San Luis Valley Recombinant Chromosome 8 [SLV Rec(8)] syndrome is strongly associated with congenital heart disease, particularly tetralogy of Fallot. This article reviews SLV Rec(8) syndrome and other chromosome 8 aberrations to suggest locations for cardiogenic genes. SLV Rec(8) [rec(8),dup q,inv(8)(p23q22)] syndrome has been found in Hispanic families in the southwestern United States. Congenital heart disease is found in 93.3% of SLV Rec(8) individuals (n = 45), with tetralogy of Fallot constituting 40.5% of all lesions and conotruncal defects, 55.6%. These frequencies exceed the incidence of tetralogy of Fallot (10%) and conotruncal defects (20%) among all children with heart defects (P less than 0.003 for both). Review of patients with deletion 8p (n = 13) showed heart defects in 84.6% with 27.3% being conotruncal defects. Among duplication 8q patients (n = 20), 45% had heart defects with conotruncal defects constituting 44%. Neither group differed significantly from expected in its incidence of conotruncal defects. Among patients with mosaic trisomy 8 (n = 47), 12 had heart abnormalities including one conotruncal defect. Among 3 patients with other rec(8) chromosomes, one had a ventricular septal defect. The cause of heart defects in SLV Rec(8) cannot be assigned to either the deletion of 8p or the duplication of 8q. The lack of an association between other chromosome 8 abnormalities and tetralogy of Fallot suggests that genes at the SLV Rec(8) breakpoints or an interaction between genes on both arms of chromosome 8 are important.

A rapid evolution mechanism may contribute to changes in sex ratio, multiple birth incidence, frequency of auto-immune disease and frequency of birth defects in Clomid conceptions

Under conditions favourable to the horizontal transmission of genetic material, a clomiphene isomer is hypothesized to encourage an alternate ovulatory route, with consequence for the sex ratio, multiple birth incidence, incidence of auto-immune disease, and frequency of malformations.

Trisomy 8 mosaicism syndrome. Two cases demonstrating variability in phenotype

The paper presents clinical manifestations and results of cytogenetic examination of two patients with trisomy 8 mosaicism syndrome. The findings confirm the extreme phenotype variability of this syndrome. Both the first patient, a mentally retarded child with multiple dysmorphic changes, and the second, a 31-year-old woman with normal IQ and hypogammaglobulinemia as a predominant sign, revealed osteoarticular anomalies. Dermatoglyphic studies in both patients were typical for trisomy 8, and correlated with deep skin furrows. The chromosomal analysis was based on two types of lymphocyte cultures: 3-day and 2-day. A decreased percentage of trisomic cells in 3-day cultures in comparison to 2-day cultures may suggest the influence of environmental factors on spontaneous elimination of trisomic cells in vitro.

Monosomy, trisomy, fragile sites, and rearrangements of chromosome no. 1 in a mentally retarded male with multiple congenital anomalies

A 17-year-old male was referred for evaluation because of short stature and severe mental retardation. Major clinical findings included microphthalmia, micrognathia, low-set ears, a prominent beaked nose, clubbing of digits, and premature graying of hair. Cytogenetic analysis revealed a 45,XY,-1/46,XY/47,XY,+1 mosaicism in lymphocytic culture, a 45,XY,-1/46,XY mosaicism in skin fibroblasts, and fra(1p) sites in 2% of the metaphases from lymphocyte, fibroblast and bone marrow cultures. Post-zygotic non-disjunction causing this mosaicism is believed to be responsible for the patient's phenotype.

A corneal abnormality associated with trisomy 8 mosaicism syndrome

Eye abnormalities are a significant feature of trisomy 8 mosaicism syndrome. This paper gives the first account of the specific histopathology of a corneal opacity which is characteristic of this syndrome. The importance of early recognition is stressed because of potential therapeutic visual improvement. The necessity of including mosaic trisomy 8 in the differential diagnosis of such corneal opacities is illustrated by this case.

Discordant monozygotic twins with trisomy 13

Monozygotic twins with typical trisomy 13 are reported. Despite an identical karyotype, the twins were dimorphic for the presence of an omphalocele. Reasons for the rarity of MZ twins with trisomy 13 are presented. It is suggested that the presence of a chromosomal abnormality in MZ twins may predispose to dimorphism.

Correlation of karyotype with patient sex and age in acute myeloid leukemia

Karyotypes were determined in 109 patients with acute myeloid leukemia. The proportions of patients with nonclonal chromosomal abnormalities, with numeric changes only, and with severe chromosomal aberrations were all found to increase to a statistically significant degree with patient age. Most patients in whom less than half of all cells were abnormal were elderly males. These results indicate that the cell karyotype was less stable in elderly patients than in younger patients. A higher frequency of nonclonal chromosomal changes was found in patients with clonal abnormalities compared with those without such abnormalities. Male patients tended to gain chromosomes and had more hyperdiploid abnormalities than female patients, who tended to lose chromosomes and had more hypodiploid abnormalities. This trend of chromosomal gain in males and loss in females mainly involved chromosomes similar in size to the sex chromosomes. Three female patients with trisomy 8 and one with 7q+ and t(8;21) showed an X chromosome twisted into a spiral shape. The results indicate that the initial karyotype effects the formation of some numeric changes. These findings are discussed in relation to possible secondary chromosomal changes and karyotypic instability.

Occurrence of sex chromosome mosaicism and translocation Down's syndrome in the same family

The proband in this family has translocation Down's Syndrome 46,XX,t(14;21)(p11;q11), and this translocation was present in other family members. Sex chromosome mosaicism was demonstrated in three generations of the family, providing another example of familial mosaicism. There was also excessive foetal wastage in different family members. It was not possible to assign the common aetiological factor to account for these various abnormalities. Dermatoglyphic studies showed dominant inheritance of finger-tip arch patterns in one branch of the family.