Two brothers with 22q13 deletion syndrome and features suggestive of the Clark-Baraitser syndrome

Sapienza University of Rome, Roma, Latium, Italy
Clinical Dysmorphology (Impact Factor: 0.61). 08/2005; 14(3):127-32. DOI: 10.1097/00019605-200507000-00004
Source: PubMed


We report on two brothers with moderate-to-severe mental retardation, severe macrocephaly, obesity, characteristic face, big hands and feet, advanced bone age and brain abnormalities, including frontal cortical atrophy. These two boys resembled the two brothers described by , two maternal cousins subsequently reported by and a Brazilian boy described by . Upon further investigation, we detected a cryptic subtelomeric deletion of chromosome region 22q13, not present in either parent and probably due to a maternal germinal mosaicism. Thus, we describe the first familial case of 22q13 deletion and recommend that patients with a phenotype suggestive of the so-called Clark-Baraitser syndrome be tested for submicroscopic 22qter deletion.

14 Reads
  • Source
    • "In particular, the thin corpus callosum and white matter and enlarged ventricles were not more severe in older patients. While few brain-imaging studies have been reported for individuals with 22q13 deletions, posterior fossa or cerebellar abnormalities were previously noted for seven patients, thin corpus callosum in another seven, and ventriculomegaly in at least three [Doheny et al., 1997; Lindquist et al., 2005; Tabolacci et al., 2005; Philippe et al., 2008; Bonaglia et al., 2011]. However, figures of brain-imaging studies were rarely provided. "
    [Show abstract] [Hide abstract]
    ABSTRACT: The 22q13.3 deletion causes a neurodevelopmental syndrome, also known as Phelan-McDermid syndrome (MIM #606232), characterized by developmental delay and severe delay or absence of expressive speech. Two patients with hemizygous chromosome 22q13.3 telomeric deletion were referred to us when brain-imaging studies revealed cerebellar vermis hypoplasia (CBVH). To determine whether developmental abnormalities of the cerebellum are a consistent feature of the 22q13.3 deletion syndrome, we examined brain-imaging studies for 10 unrelated subjects with 22q13 terminal deletion. In seven cases where the availability of DNA and array technology allowed, we mapped deletion boundaries using comparative intensity analysis with single nucleotide polymorphism (SNP) microarrays. Approximate deletion boundaries for three additional cases were derived from clinical or published molecular data. We also examined brain-imaging studies for a patient with an intragenic SHANK3 mutation. We report the first brain-imaging data showing that some patients with 22q13 deletions have severe posterior CBVH, and one individual with a SHANK3 mutation has a normal cerebellum. This genotype-phenotype study suggests that the 22q13 deletion phenotype includes abnormal posterior fossa structures that are unlikely to be attributed to SHANK3 disruption. Other genes in the region, including PLXNB2 and MAPK8IP2, display brain expression patterns and mouse mutant phenotypes critical for proper cerebellar development. Future studies of these genes may elucidate their relationship to 22q13.3 deletion phenotypes. © 2012 Wiley Periodicals, Inc.
    American Journal of Medical Genetics Part A 01/2013; 161A(1). DOI:10.1002/ajmg.a.35700 · 2.16 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: On the basis of their ever-expanding roles, not only in sensory signaling but also in a plethora of other, often Ca(2+)-mediated actions in cell and whole body homeostasis, it is suggested that mutations in TRP channel genes not only cause disease states but also contribute in more subtle ways to simple and complex diseases. A survey is therefore presented of diseases and syndromes that map to one or multiple chromosomal loci containing TRP channel genes. A visual map of the chromosomal locations of TRP channel genes in man and mouse is also presented.
    Handbook of experimental pharmacology 02/2007; 179(179):379-408. DOI:10.1007/978-3-540-34891-7_23
  • [Show abstract] [Hide abstract]
    ABSTRACT: According to the textbook of Gardner and Sutherland [2004], the standard on genetic counseling for chromosome abnormalities, the recurrence risk of de novo structural or combined structural and numeric chromosome rearrangements is less than 0.5-2% and takes into account recurrence by chance, gonadal mosaicism, and somatic-gonadal mosaicism. However, these figures are roughly estimated and neither any systematic study nor exact or evidence-based risk calculations are available. To address this question, an extensive literature search was performed and surprisingly only 29 case reports of recurrence of de novo structural or combined structural and numeric chromosomal rearrangements were found. Thirteen of them were with a trisomy 21 due to an i(21q) replacing one normal chromosome 21. In eight of them low-level mosaicism in one of the parents was found either in fibroblasts or in blood or in both. As a consequence of the low number of cases and theoretical considerations (clinical consequences, mechanisms of formation, etc.), the recurrence risk should be reduced to less than 1% for a de novo i(21q) and to even less than 0.3% for all other de novo structural or combined structural and numeric chromosomal rearrangements. As the latter is lower than the commonly accepted risk of approximately 0.3% for indicating an invasive prenatal diagnosis and as the risk of abortion of a healthy fetus after chorionic villous sampling or amniocentesis is higher than approximately 0.5%, invasive prenatal investigation in most cases is not indicated and should only be performed if explicitly asked by the parents subsequent to appropriate genetic counseling.
    American Journal of Medical Genetics Part A 08/2007; 143A(15):1708-14. DOI:10.1002/ajmg.a.31826 · 2.16 Impact Factor
Show more