Severe psychomotor delay in a severe presentation of cat-eye syndrome.

Guillaume Jedraszak,Gilles Morin,Joris Andrieux,Aline Receveur,Henri Copin,Michèle Mathieu-Dramard

doi:10.1155/2015/943905

Abstract

Cat-eye syndrome is a rare genetic syndrome of chromosomal origin. Individuals with cat-eye syndrome are characterized by the presence of preauricular pits and/or tags, anal atresia, and iris coloboma. Many reported cases also presented with variable congenital anomalies and intellectual disability. Most patients diagnosed with CES carry a small supernumerary bisatellited marker chromosome, resulting in partial tetrasomy of 22p-22q11.21. There are two types of small supernumerary marker chromosome, depending on the breakpoint site. In a very small proportion of cases, other cytogenetic anomalies are reportedly associated with the cat-eye syndrome phenotype. Here, we report a patient with cat-eye syndrome caused by a type 1 small supernumerary marker chromosome. The phenotype was atypical and included a severe developmental delay. The use of array comparative genomic hybridization ruled out the involvement of another chromosomal imbalance in the neurological phenotype. In the literature, only a few patients with cat-eye syndrome present with a severe developmental delay, and all of the latter carried an atypical partial trisomy 22 or an uncharacterized small supernumerary marker chromosome. Hence, this is the first report of a severe neurological phenotype in cat-eye syndrome with a typical type 1 small supernumerary marker chromosome. Our observation clearly complicates prognostic assessment, particularly when cat-eye syndrome is diagnosed prenatally.

Highlights

Cat-eye syndrome (CES), referred to as Schmid-Fraccaro syndrome (OMIM 115470), is a rare genetic disease with an estimated prevalence of between 1 in 50,000 and 1 in 150,000 individuals [1]
It has been observed that most patients diagnosed with CES carry a small supernumerary bisatellited marker chromosome, which results in partial tetrasomy of 22p-22q11.21
To the best of our knowledge, this is the first report of a very severe neurological phenotype in CES caused by an isolated type 1 supernumerary bisatellited marker chromosome (sSMC)

Summary

Introduction

Cat-eye syndrome (CES), referred to as Schmid-Fraccaro syndrome (OMIM 115470), is a rare genetic disease with an estimated prevalence of between 1 in 50,000 and 1 in 150,000 individuals [1]. Many reported cases feature congenital kidney abnormalities, congenital cardiac defects, intellectual disability, and growth delay. There are two types of sSMC, depending on the breakpoint site: type 1, the most frequent, involves the cat-eye syndrome critical region (CESCR) alone, whereas type 2, more rarely reported, involves both the CESCR and the DiGeorge syndrome critical region [2]. Other exceptional cytogenetic anomalies, such as partial trisomy of chromosome 22 [3] and intrachromosomal triplication of 22q11.21 region [4], are reportedly associated with the CES phenotype. We report a patient who presented with typical features of CES: imperforate anus, severe preauricular and auricular anomalies, and cardiac malformation. Type 1 sSMC involving the 22p-22q11.21 region and ruled out other chromosomal imbalances

Case Presentation

Findings

Discussion