Cat Eye Syndrome

An inherited neurodevelopmental disorder with large phenotypic variability, ranging from nearly normal to severe malformations of many organs.

Schmid-Fraccaro Syndrome; Partial Tetrasomy of Chromosome 22; Coloboma-Anal Atresia Syndrome; Ocular Coloboma-Imperforate Anus Syndrome.

In 1879 the Swiss ophthalmologist O. Haab was the first to describe a syndrome of anal atresia combined with coloboma. However, the extra chromosome 22 responsible for the syndrome was detected by W. Schmid from Zurich, Switzerland, and M. Fraccaro from Pavia, Italy, who named it cat eye syndrome (CES) because of the inferior coloboma (resulting in a vertical, cat-like pupil) and the downslanting palpebral fissures, although more than 50% of patients have no signs of coloboma.

In Switzerland, the incidence has been estimated to be 1 in 50,000-150,000 live births. This most likely is representative of other countries, as no racial predilection has been reported.

Autosomal dominant. Trisomy or tetrasomy 22 (22q11). The additional chromosome 22 generally arises de novo from one of the parents.

Not fully described.

Clinical features (mainly coloboma, anal atresia, and preauricular pits/tags) may lead to the diagnosis. However, because of the wide clinical spectrum of this disorder, the final diagnosis is made by fluorescent in situ hybridization (FISH), which shows the presence of an extra marker chromosome derived from chromosome 22 (partial extra chromosome or duplication) containing two copies of the CES region.

Clinical variability is remarkable, with the spectrum of features ranging from only minimally affected individuals to those with the full picture of malformations and lethal outcome. Minimally affected patients may show only downslanting palpebral fissures and preauricular pits or tags. However, CES usually is characterized by the combination of coloboma of the iris (unior bilateral), total or partial coloboma of the choroidea and/or optic nerve, microphthalmia (most often unilateral), downslanting palpebral fissures, preauricular tags and/or pits, and anal atresia with rectovesical, rectovaginal, or rectovulvar fistulas in females and rectovesical, rectourethral, or rectoperineal fistulas in males. Other frequently encountered anomalies include renal anomalies (absence of one or both kidneys, supranumeric kidneys, renal hypoplasia, hydronephrosis) and congenital cardiovascular malformations (tetralogy of Fallot, total anomalous pulmonary venous drainage, persistent left superior vena cava, Eisenmenger complex) in more than one third of patients. Additional craniofacial stigmata may include aniridia, cataract, hypertelorism, strabismus, inner epicanthic folds, flat nasal bridge, choanal atresia, cleft lip and palate, mandibular hypoplasia, additional ear malformations (reduction of the auricles to several tags only and atresia of the external auditory canal), and hypothalamic growth hormone deficiency (without severe growth retardation). Skeletal anomalies may present as absence or synostosis of ribs, scoliosis, vertebral fusions, and limb malformations (radial aplasia, duplication of the hallux, absent toes and sirenomelia). Visceral anomalies include pulmonary segmentation defects, intestinal malrotation, biliary atresia, Hirschsprung disease, Meckel diverticulum, umbilical hernia, uterus hypoplasia and vaginal atresia in girls, and hypospadia in boys. Cases of CES in combination with spina bifida or myelomeningocele have been reported. Normal or only slightly delayed mental development is common, but in rare cases, patients with the full picture of the syndrome have severe mental retardation.

Except for minimally affected patients, all patients will require surgery at some point (anal atresia, congenital heart malformations). Preoperative blood work should include a complete blood count, evaluation of renal function (blood urea nitrogen, creatinine), and hepatic function tests (transaminases, bilirubin, ammonia, albumin, coagulation profile). Cardiac lesions should be investigated by echocardiography and/or cardiac catheterization. Evaluate the airway clinically (possibly by radiography) for anesthetic management. Check for choanal atresia.

Micrognathia and limited mouth opening may make direct laryngoscopy and tracheal intubation difficult. Alternative airway management techniques may be necessary (e.g., awake fiberoptic intubation, [intubating] laryngeal mask airway). Choanal atresia precludes nasal intubation. Regional anesthetic techniques do not appear to be specifically contraindicated (given coagulation is normal), but central neuraxial blockade could be difficult secondary to vertebral anomalies. Limb malformations could make the blood pressure cuff difficult to apply. Radial aplasia may render radial artery cannulation difficult or impossible. Mental retardation may impair cooperation. Sedative and/or anxiolytic premedication and the presence of the primary caregiver during induction of anesthesia may be helpful.

The selection of anesthetic agents is influenced by the degree of associated renal and hepatic dysfunction and the underlying cardiac lesion. Subacute bacterial endocarditis prophylaxis may be indicated.

Cat Cry Syndrome: A syndrome associated with a high-pitched, cat-like cry in the newborn period, severe mental retardation, facial anomalies, scoliosis, muscular hypotonia and congenital cardiac defects.