| We report a case of mosaic trisomy 22 in a Japanese neonate. A female neonate weighing 1,700 g was delivered at a
gestational age of 36 weeks and 1 day. Dysmorphic features noticed at birth included microcephaly, hypertelorism, downslanted
palpebral fissures, blepharophimosis, depressed nasal bridge, low-set ears, micrognathia, cleft palate, overlapping
fingers, small nails, and neck webbing. Congenital heart defects, including double outlet right ventricle, ventricular and
atrial septal defects, pulmonary atresia, and patent ductus arteriosus were identified by echocardiogram. She required
intensive treatment, including mechanical ventilation and cardiovascular surgery. Also present were laryngomalacia,
upper airway obstruction, dysphagia, gastroesophageal reflux, hearing loss, body asymmetry, failure to thrive, and
mental retardation. Standard G-banded chromosomal analysis of peripheral blood lymphocytes showed mos 47, XX, ＋
22[7]/46, XX[53]. Mosaic trisomy 22 is a rare chromosomal disorder. It is possible that children with this disorder are
underdiagnosed because of a low level of mosaicism in blood cells. Therefore, appropriate data compilation regarding
clinical features and cytogenetic testing is needed. |
