Trisomy 9

Chromosomal disorder that can occur in a mosaic or nonmosaic expression, in which all major systems are significantly involved. Clinically characterized by severe gastrointestinal problems, scoliosis and kyphosis, repetitive periods of apnea, complex congenital heart defects, severe immunological disorders, failure to thrive, and severe mental retardation. Death occurs in infancy or early childhood.

Chromosome 9 Trisomy Syndrome.

Caused by excessive synthesis by an extra chromosome and varies with the characteristic of the trisomy (total or mosaic).

Clinically evocated by psychomotor retardation and multiple abnormalities of the craniofacial structures, heart, skeletal system, extremities, and other organs; confirm by karyotype studies.

This is a severe disease with growth and mental retardation. Death occurs generally in infancy or early childhood. Clinical features involve all major systems. Cerebral and craniofacial malformations are constant (Dandy-Walker cyst; subependymal cysts; ventricular dilatation of the brain; microcephaly; prominent occiput micrognathia; wide cranial sutures and fontanels; craniosynostosis; facial cleft and cloverleaf skull; short and up-slanting palpebral fissures; microphthalmia; coloboma; corneal clouding; hypertelorism; deeply set eyes; low-set malformed ears; tongue abnormalities; ankyloglossia; cleft lip/palate). Skeleton abnormalities can include short and webbed neck, hip dislocation, abnormally shaped long bones, limitation of joint movement, short limbs, and dysplasia of hands and feet. Other clinical features include heart (ventricular septal defect, atrial septal defect, patent ductus arteriosus, valve defects, double-outlet right ventricle, persistent left superior vena cava, endocardial fibroelastosis), urogenital system (hydronephrosis, duplication of collecting system, microcystic kidneys, dysplastic kidneys, cryptorchidism, small penis, hypospadias, hypoplastic labia), and skin (deep palmar and plantar creases, hyperconvex nails).

Evaluate cardiac function (clinical, echocardiography, ECG), renal function (echography, urea, creatinine, electrolytes), and tracheal intubation (clinical, radiography).

Direct laryngoscopy and tracheal intubation can be difficult because of short neck, ankyloglossia, and microretrognathia, and may require fiberoptic or retrograde intubation. Spontaneous respiration must be maintained until tracheal intubation is achieved and lung ventilation confirmed. A laryngeal mask airway and/or fiberoptic equipments should be readily available. Venous access can be difficult as a result of limb anomalies. Careful intraoperative positioning is necessary considering hip dislocation and joint limitation. Pulse oximetry can be difficult because of nail malformation.

Prophylactic antibiotics should be given as indicated in cases of cardiac defect. Preserve spontaneous ventilation before intubation is performed and avoid anesthetic drugs with marked cardiovascular effects.

Duplication 9p Partial (Trisomy 9p Partial): Pupillary anomalies, kyphoscoliosis, and gastroesophageal reflux.

Duplication 9q32 (Trisomy 9q32): Chronic inflammatory lung disease, hypotonia, and microstomia.

Partial Trisomy 9q (Chromosome 9q Duplication Syndrome): Psychomotor retardation, deeply set eyes, microdolichocephaly, beaked nose, and microretrognathia.