Kyriaki Kekou

Tall Stature, Insulin Resistance, and Disturbed Behavior in a Girl with the Triple X Syndrome Harboring Three SHOX Genes: Offspring of a Father with Mosaic Klinefelter Syndrome but with Two Maternal X Chromosomes

Aims: To describe the tall stature and its possible underlying mechanism in a Caucasian girl (age 12 years and 10 months) with 46,XX (28%)/47,XXX (72%) mosaicism and to identify the parental origin of her extra X chromosome. Methods: The fasting glucose-to-insulin ratio was studied. The karyotypes of the girl and her parents as well as the presence of SHOX copies and the parental origin of her extra X chromosome were assessed. Results: Clinical examination revealed a tall stature and severe acne, and endocrinological/metabolic assessment revealed insulin resistance. Fluorescence in situ hybridization cytogenetic analysis depicted the presence of three SHOX genes in the 47,XXX cell line of the patient. Karyotyping of her parents showed a normal 46,XX karyotype in the mother and 46,XY(93%)/47,XXY(7%) Klinefelter mosaicism in the father. However, DNA analysis unequivocally showed maternal origin of the extra X chromosome of the patient. Conclusions: This report suggests that SHOX gene triplication may produce a tall stature, even in the presence of preserved ovarian function. X triplication might predispose to insulin resistance and behavioral disorders.

Screening Human Genes for Small Alterations Performing an Enzymatic Cleavage Mismatched Analysis (ECMA) Protocol

Many human diseases are caused by small alterations in the genes and in the majority of cases sophisticated protocols are required for their detection. In this study we estimated the efficacy of an enzymatic protocol, which using a new mismatch-specific DNA plant endonuclease from celery (CEL family) recognizes and cleaves mismatched alleles between mutant and normal PCR products. The protocol was standardized on a variety of known mutations, in 11 patients with cystic fibrosis (CF), Fabry’s disease (FD), steroid 21-hydroxylase deficiency (21-HD), and Duchenne/Becker muscular dystrophy (DMD/BMD). The method does not require special equipment, labeling or standardization for every PCR product, since conditions of heteroduplex formation and enzyme digestion are universal for all products. The results showed that the method is rapid, effective, safe, reliable, and very simple, as the mutations are visualized on agarose or nusieve/agarose gels. The protocol was furthermore evaluated in three DMD patients with the detection of three alterations, which after sequencing, were characterized as disease causative mutations. The proposed assay, which was applied for the first time in a variety of monogenic disorders, indicates that point mutation identification is feasible in any conventional molecular lab even for cases where other techniques have failed.

Caveolinopathies in Greece.

Introduction: Mutations in the CAV3 gene are usually inherited in an autosomal dominant manner and lead to distinct disorders including limb-girdle muscular dystrophy 1C, rippling muscle disease, and isolated creatine kinase elevation. Patients and Methods: The features of the first patients with caveolin-3 deficiency from Greece are presented. Patients’ phenotypes ranged from asymptomatic creatine kinase elevation to severe weakness of lower extremities. Clinical evaluation disclosed muscle hypertrophy in 2 patients, whereas percussion-induced muscle mounding was a consistent finding in all of them. Muscle histopathology was variable and unrelated with disease severity. The diagnosis was based on the immunohistochemical study of caveolin-3 expression and molecular analysis of the caveolin-3 gene. Conclusions: Clinical manifestations and histochemical findings in caveolinopathy patients may be mild or nonspecific or overlapping with features of other muscular dystrophies. Immunohistochemical study of caveolin-3 expression on muscle biopsy should be routinely performed when investigating isolated hyperCKemia or undetermined myopathy especially in the presence of percussion-induced muscle mounding.

Analysis of a founder mutation in the TH gene in a cohort of greek patients with Parkinson's disease.

of the index family in our studies; without their support, this work would not have been possible. This study was supported by the TGen Foundation, the Phoenix Children’s Hospital Foundation, and by grants from the Child Neurology Foundation (Shields Award to MCK) and the Dystonia Medical Research Foundation (MCK). The authors also acknowledge the contributions of the C4RCD Research Group. This group includes the clinical and laboratory research team involved in patient enrollment, sample processing, exome sequencing, data processing, preparation of variant annotation files, data analysis, validation of data, and return of research data to families. Candidate genes are identified and discussed at data analysis meetings of the entire group. The following members of the group (listed in alphabetical order) have contributed significantly to this work: Newell Belnap (nbelnap@tgen.org), Megan Russell (mrussell@tgen.org), Amanda Courtright (acourtright@tgen.org), Matt de Both (mdeboth@tgen.org), Ana Claasen (aclaasen@tgen.org), Ahmet Kurdoglu (akurdoglu@tgen.org; akurdoglu@ashiondx.com), Sampathkumar Rangasamy (srangasamy@tgen.org), Ryan Richholt (rrichholt@tgen.org), Isabelle Schrauwen (ischrauwen@tgen.org), Ashley L. Siniard (asiniard@ tgen.org), Szabolics Szelinger (sszelinger@tgen.org).

A single amino acid loss in the dystrophin protein associated with a mild clinical phenotype.

Introduction: The dystrophinopathies include a spectrum of muscle diseases caused by mutations in the dystrophin (DMD) gene. The clinical phenotype ranges from severe Duchenne muscular dystrophy to a mild phenotype with elevated creatine kinase (CK). Methods: Clinical and molecular assessment of 7 patients carrying a single amino acid loss in the dystrophin protein (p.His1690del) caused by a c.5068_5070delCAC tri‐nucleotide deletion in exon 36 of the DMD gene. Results: All patients were asymptomatic or oligosymptomatic and had elevated CK levels. Febrile illness, but not exercise, induced muscle symptoms in some patients. None had evidence of cardiomyopathy. Analysis of the short tandem repeat (STR)45 locus and sequencing of exon 36 of the DMD gene indicates that c.5068_5070delCAC is a founder mutation. Conclusions: The c.5068_5070delCAC locus in the DMD gene is associated with a very mild phenotype. Further study is needed to evaluate disease progression in these patients. Muscle Nerve 55: 46–50, 2017

SURVEYOR on the Spot: Strengths and Weaknesses in Molecular Diagnostics

This correspondence addresses J Mol Diagn 2009, 11:311–318, on the advantages and disadvantages of using SURVEYOR in molecular diagnostic mutation detection.

A dynamic trinucleotide repeat (TNR) expansion in the DMD gene

Dystrophinopathies are allelic X-linked myopathies caused by large deletions/duplications or small lesions along the DMD gene. An unexpected dynamic trinucleotide (GAA) expansion, ranging from ∼59 to 82 pure GAA repeats, within the DMD intron 62, was revealed to segregate through three family generations. From the pedigree, two female patients were referred for DMD investigation due to chronic myopathy and a muscle biopsy compatible with dystrophinopathy. As the size of the GAA repeat is limited to 11-33 within the general population our findings may provide a novel insight towards a Trinucleotide Repeat Expansion. Whether this TNR has an impact on the reported phenotype remains to be resolved.