Gastrointestinal abnormalities in the syndrome of mosaic trisomy 9.

Gastrointestinal abnormalities in the syndrome of mosaic trisomy 9The proband, an 18 month old child, was delivered by caesarian section after an uneventful 38 week gestation, birth weight 2400 g.She was the fourth daughter of healthy, non-consanguineous parents aged 43 and 40 years at the time of birth.The family history was unremarkable.From the age of six months, the child has been examined repeatedly for clinical and radiological findings of upper and lower respiratory tract infections.At the age of 18 months she was admitted to our department because of massive right lower lobe pneumonia.Physical examination showed a child with severe failure to thrive and moderate psychomotor retardation whose weight was 7500 g (below the 3rd centile), height 71 cm (below the 3rd centile), and head circumference 45 cm (25th centile).The sagittal suture and anterior fontanelle were widely open.She had bilateral microphthalmia, deep set eyes, short palpebral fissures, broad nasal bridge, and bulbous nose.The palate was highly arched and the ears were low set and posteriorly rotated.No heart murmurs were audible.She also had acrocyanosis with distal mottling and non-pitting oedema of both legs.Adduction of both hips was limited to 20°.Neurological assessment showed generalised marked hypotonia and hyporeflexia of the deep tendon reflexes.She could neither sit by herself nor stand or crawl.Her fine motor performance and speech capability were retarded.Skull x ray showed a widely open fontanelle and sagittal suture.Chest x ray showed right sided aortic arch with infiltrates of the right lower lobe and thickening of the bronchial tree.Pelvic x ray showed bilateral coxa valga.CT scan of the brain and renal ultrasound were normal.Echocardiography showed right aortic arch with no other cardiac anomalies.A barium swallow was regurgitated up to the oral cavity and aspirated, indicating that the reflux and malfunction- ing of the swallowing mechanism could be the underlying cause of the repeated pulmonary infections.Kidney and liver function tests, as well as endocrinological and sweat tests, were within normal limits.Cytogenetic studies performed on peripheral blood lymphocytes, cultured with phytohaemagglutinin for 72 hours, indicated that 70 out of 100 cells (70%) had a normal female karyotype (46,XX) and 30 cells (30%) were trisomic for chromosome 9, 47,XX,+9 (figure).Mosaic trisomy 9 is a rare chromosomal aberration.Only 23 cases of this trisomy have been previously reported, some of them complete, and some of them with mosaic trisomy 9.The affected children show failure to thrive, multiple craniofacial anomalies, musculoskeletal, cardiac,