Prenatal diagnosis of nonmosaic trisomy 9 and related ultrasound findings at 11.7 weeks

Trisomy 9 mosaic syndrome: Sixteen additional patients with new and/or less commonly reported features, literature review, and suggested clinical guidelines

Trisomy 9 mosaic syndrome (T9M) is a rare condition characterized by multiorgan system involvement including craniofacial dysmorphisms, cardiac, genitourinary (GU), skeletal, and central nervous system (CNS) abnormalities. Although more than 100 cases have been reported in the literature, a comprehensive review has not been performed nor have clinical guidelines been established. Therefore, we describe the clinical features of 16 additional patients, review features of previously reported individuals, and suggest clinical guidelines. Our findings expand the clinical phenotype of T9M, including novel features of amblyopia, astigmatism, corectopia of pupil, posterior embryotoxon, and diaphragmatic eventration. Most patients had prenatal and perinatal issues, particularly from respiratory, growth, and feeding standpoints. Although small birth parameters were common, long-term growth trends varied widely. An association with advanced parental ages was also identified. The spectrum of growth and development was wide, ranging from nonverbal patients to those able to participate in educational programs with age-appropriate peers. The severity of clinical outcomes was unrelated to blood lymphocyte mosaicism levels. Microarray analysis had a higher diagnostic rate compared to standard karyotype analysis and should be utilized if this diagnosis is suspected. Future longitudinal studies will be key to monitor long-term outcomes of individuals with T9M and determine best practices for clinical management.

Ultrasound diagnosis of central nervous system anomalies (bifid choroid plexus, ventriculomegaly, Dandy-Walker malformation) associated with multicystic dysplastic kidney disease in a trisomy 9 fetus: case report with literature review

Trisomy 9 is a lethal chromosomal abnormality that rarely progresses beyond the second trimester of pregnancy. Multiple central nervous system anomalies, including bifid choroid plexus, ventriculomegaly, and Dandy-Walker malformation, associated with multicystic dysplastic kidney disease in a trisomy 9 fetus are reported. The prenatal ultrasound diagnosis has been aided by novel three-dimensional ultrasound software.

Clinical manifestations in trisomy 9

Complete trisomy 9 is a lethal diagnosis and most fetuses diagnosed thus die prenatally or during the early postnatal period and majority of such cases have been known to end in spontaneous abortion in the first trimester itself. One such rare survival of fetus ending in normal delivery and surviving until 20 days is reported here detailing the clinical manifestations of the child during the period of survival. The salient clinical features observed were small face, wide fontanel, prominent occiput, micrognathia, low set ears, upslanting palpebral fissures, high arched palate, short sternum, overlapping fingers, limited hip abduction, rocker bottom feet, heart murmurs and also webbed neck, characteristic of this trisomy 9 syndrome.