Schmid-Fraccaro syndrome: severe neurologic features

Embryology, Malformations, and Rare Diseases of the Cochlea

Despite the low overall prevalence of individual rare diseases, cochlear dysfunction leading to hearing loss represents a symptom in a large proportion. The aim of this work was to provide a clear overview of rare cochlear diseases, taking into account the embryonic development of the cochlea and the systematic presentation of the different disorders. Although rapid biotechnological and bioinformatic advances may facilitate the diagnosis of a rare disease, an interdisciplinary exchange is often required to raise the suspicion of a rare disease. It is important to recognize that the phenotype of rare inner ear diseases can vary greatly not only in non-syndromic but also in syndromic hearing disorders. Finally, it becomes clear that the phenotype of the individual rare diseases cannot be determined exclusively by classical genetics even in monogenetic disorders.

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

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.

Coloboma and anorectal malformations: a rare association with important clinical implications

PURPOSE

In a patient with an anorectal malformation (ARM), the presence of a coloboma is commonly associated with other serious anomalies.

METHODS

Our database and the world literature were reviewed searching for associated defects in patients with ARM and coloboma.

RESULTS

Of 2,482 ARMs in our database, 11 had coloboma (0.4%): 2 were females. No specific associated type of ARM was identified. Six patients were developmentally delayed. Eight had a cardiac anomaly (3 had TAPVR, 2 VSD, 3 ASD), five required a cardiac operation. Five had a gastrointestinal anomaly (3 malrotation, 1 biliary and 1 duodenal atresia). Six had eye and seven had ear anomalies. Five had a genetic abnormality. In the literature, 71 patients with ARM and coloboma were found: 65 % were females. 24% died prematurely. 74% were developmentally delayed. 70% had a cardiac malformation (35% had TAPVR, 38% required an operation). 57% had gastrointestinal anomalies (31% malrotation, 31 % biliary atresia, 17% Hirschsprung disease). Eye and ear anomalies were present in 80 and 97% of patients, respectively. 81% had a genetic abnormality.

CONCLUSIONS

An ocular inspection in patients born with ARM is crucial. The finding of a coloboma should increase awareness to evaluate for a developmental, cardiologic or gastrointestinal anomaly.

A de novo sSMC(22) Characterized by High-Resolution Arrays in a Girl with Cat-Eye Syndrome without Coloboma

Cat-eye syndrome (CES) results from trisomy or tetrasomy of proximal 22q originated by a small supernumerary marker chromosome (sSMC). Two critical regions for the major clinical features of CES (CESCRs) have been suggested; however, CES clinical presentation often does not correlate with the sSMC genetic content. We report here a CES girl without coloboma and carrier of a de novo type I sSMC(22) as determined by G- and C-banding, NOR staining and microarrays. This sSMC included 6 distal genes outside the original CESCR and led to a tetrasomy for 22q11.1-22q11.21. The patient's final karyotype was 47,XX,+psu dic(22)(q11.21).arr 22q11.1q11.21(15,250,000-17,035,860)×4 dn. The amplified region outside of CESCR included some genes that may be related to neurologic, heart and renal abnormalities. Conversely, even though the amplification included the CECR2 gene, a major candidate for eye features, there was no coloboma in the patient. The genetic delineation of the present sSMC further strengthens that the CES clinical presentation does not fit completely with the duplicated genetic content and that CES is actually a genomic disorder. Furthermore, since we observed no mosaicism, we believe that other mechanisms might be behind the variability of CES phenotypes as well, mainly those related with functional interactions among amplified genes.