Cat eye syndrome (CES) is the congenital cytogenetic abnormality that results from the presence of an extra chromosomal fragment (tetrasomy 22pter-22q11). Most people with cat eye syndrome present with the partial absence of tissue from the eye (coloboma). The degree of other malformations varies significantly, ranging from very mild to severe.
Presentation
The malformations associated with cat eye syndrome span a broad clinical spectrum [1] [2]. Commonly occurring malformations include preauricular anomalies, anal atresia, and coloboma of the iris. The following malformations are associated with CES [2] [3] [4]:
- Eye: A majority of patients with CES present with coloboma of the iris, choroid, and/or the retina; coloboma may occur unilaterally or bilaterally. The iris may have a "keyhole" appearance due to the absence of iris tissue (aniridia). Other, less common, features include clouding of the cornea, microphthalmia, cataract, and/or Duane syndrome [3].
- Ears: Phenotypic abnormalities of the ears consist of small outgrowths of skin or preauricular tags and/or pits, low-set or small ear size, and/or atresia or absent external ear canals [2].
- Head/neck: Craniofacial malformations such as mandibular hypoplasia, cleft lip, down-slanting palpebral fissures, hypertelorism, inner epicanthic folds, and/or flat nasal bridge may be present [5].
- Gastrointestinal (GI): GI malformations include an umbilical hernia, intestinal malrotation, biliary atresia, and/or Hirschsprung disease.
- Genitourinary (GU): A significant number of patients with CES present with anal atresia. Less commonly, patient's may have an anorectal fistula into the vagina (in females), bladder, urethra, or perineum [3]. Males with CES may have undescended testes or hypospadias [6].
- Cardiac: Congenital heart defects associated with CAE include total anomalous pulmonary venous return or tetralogy of Fallot [7].
- Renal: Kidney malformations consist of renal atresia, hydronephrosis, supernumerary kidneys, and/or renal hypoplasia of one or both kidneys.
- Musculoskeletal: Spinal defects and limb malformations (e.g., radial aplasia, duplication of the hallux, absent toes and sirenomelia), absence or synostosis of ribs, scoliosis, and/or vertebral fusions have been observed in patients with CES [3].
- Cognitive: No cognitive impairment to moderate intellectual disability have been reported; most individuals with CES have a mild degree of intellectual impairment.
Entire Body System
- Fishing
FISH studies demonstrated that the marker is a derivative of chromosome 22 and enabled us to provide the family with additional prognostic information. [ncbi.nlm.nih.gov]
Fluorescence in situ hybridization (FISH) with specific probes is needed to detect a low level mosaicism. [orpha.net]
Eyes
- Antimongoloid Slant
Additionally, the patient had antimongoloid slant of the eyes, epicanthal folds, preauricular sinuses, cardiac malformations, skeletal malformations, and mental retardation suggestive of the cat-eye syndrome. [ncbi.nlm.nih.gov]
Musculoskeletal
- Torticollis
Here, we present a 9-month-old female who at birth was noted to have multiple defects, including facial asymmetry with asymmetric retrognathia, bilateral mandibular hypoplasia, branchial cleft sinus, right-sided muscular torticollis, esotropia, and an [ncbi.nlm.nih.gov]
- Genu Valgum
Clinically the patient shows: moderate psychic retardation, high forehead, epicanthus, strabismus, microretrognathism, large, low inserted ears, kypho-scoliosis, genu valgum; mild hypothyroidism. [ncbi.nlm.nih.gov]
Breast
- Widely Spaced Nipples
On examination, she had microcephaly, periorbital puffiness, a long philtrum, a broad nasal bridge and retrognathia, up slanting palpebral fissures, widely spaced nipples, a sacral dimple and right upper limb postaxial polydactyly. [ncbi.nlm.nih.gov]
- Fissure of the Nipple
On examination, she had microcephaly, periorbital puffiness, a long philtrum, a broad nasal bridge and retrognathia, up slanting palpebral fissures, widely spaced nipples, a sacral dimple and right upper limb postaxial polydactyly. [ncbi.nlm.nih.gov]
Face, Head & Neck
- Broad Nasal Bridge
On examination, she had microcephaly, periorbital puffiness, a long philtrum, a broad nasal bridge and retrognathia, up slanting palpebral fissures, widely spaced nipples, a sacral dimple and right upper limb postaxial polydactyly. [ncbi.nlm.nih.gov]
- Neck Mass
We present the clinical and molecular findings of a 9-month-old girl with features of CES and also a palpable midline neck mass proved to be an extragonadal mature teratoma, additionally characterized by array comparative genomic hybridization (aCGH). [ncbi.nlm.nih.gov]
Urogenital
- Primary Amenorrhea
Although Müllerian agenesis is the second most common cause of primary amenorrhea the underlying etiology in most cases is unknown. [ncbi.nlm.nih.gov]
Workup
Cat eye syndrome is diagnosed using multimodal testing. Detection of a fetal abnormality on a routine prenatal ultrasound is often the first indication for a need of additional workup. Amniocentesis, chorionic villus sampling, or blood-based genetic testing (non-invasive prenatal testing) are used to perform a fetal chromosomal analysis prenatally. Tetrasomy of chromosome 22 is highly suggestive of cat eye syndrome [8] [9]. The extent of malformations and the organs affected in utero are determined using ultrasound.
Cat eye syndrome can be detected after birth by physical examination, clinical evaluations, and chromosomal analysis. The physical exam should consist of screening for phenotypic features of cat eye syndrome such as coloboma and periauricular abnormalities. Clinical evaluation is performed using computed tomography of the chest and abdomen to identify malformations of internal organs and organ-based testing (e.g., echocardiography, ultrasound, neuro- or musculoskeletal MRI, eye exam, hearing test).
Molecular tests including whole chromosome paint, chromosomal analysis, FISH, array genomic hybridization and/or the Multiplex Ligation-dependent Probe Amplification assay are used to confirm the diagnosis of cat eye syndrome [8] [10] [11].
Treatment
The material is in no way intended to replace professional medical care by a qualified specialist and should not be used as a basis for diagnosis or treatment. [orpha.net]
Treatment Treatment is given according to the symptoms the individual is diagnosed with. Doctors recommend surgery to repair inborn defects in the heart or anus. Patients with short stature are given growth hormone therapy. [content.achhabachha.com]
Prognosis
Prognosis Some patients die from severe malformations in early infancy. Otherwise, life expectancy is generally not significantly reduced. The documents contained in this web site are presented for information purposes only. [orpha.net]
Etiology
Although Müllerian agenesis is the second most common cause of primary amenorrhea the underlying etiology in most cases is unknown. [ncbi.nlm.nih.gov]
Etiology Most patients harbor a small supernumerary bisatellited marker chromosome (sSMC) that results in partial tetrasomy of 22pter-22q11. In one third of cases, this extra chromosome is present in a mosaic state. [orpha.net]
Epidemiology
Summary Epidemiology CES has an estimated prevalence of 1/50,000 to 1/150,000 live births. Males and females appear to be affected equally. [orpha.net]
Pathophysiology
1. anaemia 2. apnea 3. apnoea 4. arrhythmia 5. cardiovascular 6. decompensation 7. distress 8. dysrhythmia 9. dysrhythmias 10. haemolysis 11. hemolysis 12. hypercapnia 13. hypoxemia 14. hypoxia 15. illness 16. illnesses 17. malfunction 18. pathophysiology [onelook.com]
Prevention
Prevention Since Cat eye syndrome is a genetic disorder, no preventative measures can be taken against the disorder. < Previous Click below links to know more – [content.achhabachha.com]
References
- Behrman RE, Richard E. Kliegman, Robert
Jenson, Hal B et al., eds. Nelson Textbook of Pediatrics. 16th ed. Philadelphia, PA: W.B. Saunders Company; 2000:1385-89, p. 1399-1400. - Berends MJ, Tan-Sindhunata G, Leegte B, et al. Phenotypic variability of cat-eye syndrome. Genet Couns. 2001;12:23–34.
- Buyse ML. Birth Defects Encyclopedia. Dover, Mass: Blackwell Scientific Publications, Inc; 1990:287-88.
- Rosias PR, Sijstermans JM, Theunissen PM, et al. Phenotypic variability of the cat eye syndrome. Case report and review of the literature. Genet Couns. 2002;12:273-82.
- Gorlin RJ, Michael C, Raoul CM, et al., eds. Syndromes of the Head and Neck. 3rd ed. New York, NY: Oxford University Press; 1990:95-96, 881-2.
- Masukawa H, et al. Cat eye syndrome with hypogonadotropic hypogonadism. Intern Med. 1998;37:853-6.
- Braunwald E. Heart Disease: A Textbook of Cardiovascular Medicine. 3rd ed. Philadelphia, Pa; WB Saunders Company; 1988:961-3.
- Kurahashi H, Shaikh TH, Zackai EH, et al. Tightly clustered 11q23 and 22q11 breakpoints permit PCR-based detection of the recurrent constitutional t (11; 22). Am J Hum Genet. 2000;67;763–8.
- McDermid HE, Morrow BE. Genomic disorders on 22q11. Am J Hum Genet. 2002;70:1077–88.
- Vorstman JAS, Jalali GR, Rappaport EF, et al. MLPA: a rapid, reliable, and sensitive method for detection and analysis of abnormalities of 22q. Hum Mutat. 2006;27:814–21.
- Liehr T, Pfeiffer RA, Trautmann U. Typical and partial cat-eye syndrome: identification of the marker chromosome by FISH. Clin Genet. 1992;42:91–6.