Prenatal diagnosis of trisomy 6 mosaicism

Abstract

We report on a fetus with multiple congenital anomalies detected at the prenatal ultrasound examination and a trisomy 6 mosaicism in the amniocytes. The pregnancy was interrupted in the 18th gestational week and the autopsy revealed malformations including cleft right hand, arthrogryposis and hypoplasia of the 4th digit of the left hand, syndactylies and overlapping toes, facial dysmorphism with hypertelorism and low-set ears, ventricular septum defect (VSD), intestinal malrotation and scoliosis. Trisomy 6 mosaicism was detected in cultured amniocytes (13.3%), confirmed in umbilical cord fibroblasts (40%) and by fluorescence in situ hybridization on other fetal tissues. Trisomy 6 mosaicism is a very rare finding with only eight cases previously reported to our best knowledge.

Arthrogryposis: A Review and Update

“…Chromosomal deletions or rearrangements are an occasional cause of arthrogryposis 43,44 . Developmental loss of facial and other brainstem motor neurons (e.g., Moebius syndrome) is also sometimes associated with arthrogryposis.…”

Prenatal diagnosis of trisomy 6 rescue resulting in paternal UPD6 with novel placental findings

“…Similar to our case, most of these reports represented low‐level trisomy 6 mosaicism detected through amniocentesis followed by delivery of a diploid fetus; although the fetuses were phenotypically normal in the reported cases, none had documented UPD6. Only three fetuses with mosaic trisomy 6 and congenital malformations have been described, all of them with confirmed trisomy mosaicism in fetal tissues and no documentation of UPD6 [Miller et al, 2001; Wegner et al, 2004; Destree et al, 2005]. On the other hand, none of the previously reported cases of paternal UPD6 had documentation of associated trisomy 6, or a prenatal diagnosis of abnormalities involving chromosome 6.…”

Ocular manifestations in Edward's syndrome, a case report and literature review

“…Trisomy 18, also known as Edward's syndrome, is defined as a hereditary disorder, presenting with an extra chromosome 18 in the karyotype study. 1 , 2 , 3 , 4 This syndrome is the second most common autosomal disorder among live-born children after trisomy 21. It is estimated that one in every 3000 to 10,000 live births is diagnosed with Edward's syndrome.…”

“…It is estimated that one in every 3000 to 10,000 live births is diagnosed with Edward's syndrome. 3 , 4 , 5 Of these, less than 10% survive through the first year. As most male infants with the disease die during pregnancy, it is believed that most live-born children with trisomy 18 are females; thus, there is a 3:1 ratio in the prevalence of females to males.…”

“…As most male infants with the disease die during pregnancy, it is believed that most live-born children with trisomy 18 are females; thus, there is a 3:1 ratio in the prevalence of females to males. 4 , 5 , 6 This syndrome affects multiple organs, leading to neurological, cardiac, pulmonary, gastrointestinal, musculoskeletal manifestations. 6 , 7 In the present article, we reported a three-year-old girl with ocular presentations of Edward's syndrome as esotropia (ET), optic atrophy, and pigmentary retinopathy.…”