Biomedical subjects

Krystyna Chrzanowska

Publications and source records attributed to Krystyna Chrzanowska.

5 recordsLinked to original sources

PubMed2026

Unexpected Virilization in a Patient with Turner Syndrome with Unbalanced Y/7 Translocation in the Gonadal Tissue: Gonadoblastoma Diagnosis.

Turner syndrome (TS) may involve tissue-restricted mosaicism, undetectable in standard peripheral blood karyotyping. This poses a diagnostic challenge, particularly when occult Y-chromosome material increases gonadoblastoma risk. We report an 18-year-old girl with TS (45,X), short stature on recombinant human growth hormone and severe intellectual disability, who developed virilization at age 12. Laboratory testing showed hypergonadotropic hypogonadism with elevated testosterone. Imaging failed to detect gonads. Bilateral gonadectomy revealed streak gonad tissue and testicular tissue with intratubular germ cell neoplasia and focal gonadoblastoma. High-resolution cytogenetics confirmed gonadal mosaicism with unbalanced Y/7 translocation, absent in lymphocytes. This case highlights that unexplained virilization in TS warrants immediate evaluation and that high-resolution genomic methods and timely gonadectomy are essential for cancer risk reduction.

Humans↗

PubMed2006

Impaired elimination of DNA double-strand break-containing lymphocytes in ataxia telangiectasia and Nijmegen breakage syndrome.

The repair of DNA double-strand breaks is critical for genome integrity and tumor suppression. Here we show that following treatment with the DNA-intercalating agent actinomycin D (ActD), normal quiescent T cells accumulate double-strand breaks and die, whereas T cells from ataxia telangiectasia (AT) and Nijmegen breakage syndrome (NBS) patients are resistant to this death pathway despite a comparable amount of DNA damage. We demonstrate that the ActD-induced death pathway in quiescent T lymphocytes follows DNA damage and H2AX phosphorylation, is ATM- and NBS1-dependent and due to p53-mediated cellular apoptosis. In response to genotoxic 2-Gy gamma-irradiation, on the other hand, quiescent T cells from normal donors survive following complete resolution of the damage thus induced. T cells from AT and NBS patients also survive, but retain foci of phosphorylated H2AX due to a subtle double-strand break (DSB) repair defect. A common consequence of these two genetic defects in the DSB response is the apparent tolerance of cells containing DNA breaks. We suggest that this tolerance makes a major contribution to the oncogenic risk of patients with chromosome instability syndromes.

Apoptosis↗

PubMed2006

The ARX mutations: a frequent cause of X-linked mental retardation.

The ARX gene mutations have been demonstrated to cause different forms of mental retardation (MR). Beside FMR1, in families with X-linked mental retardation (XLMR), the ARX dysfunction was demonstrated to be among the most frequent causes of this heterogeneous group of disorders. Nevertheless, in sporadic cases of MR, ARX mutations are extremely rare. In order to evaluate the frequency of ARX mutation in XLMR, we performed mutational analysis of ARX in 165 mentally retarded probands negative for FRAXA and belonging to families in which the condition segregates as an X-linked condition. The same recurrent mutation, an in frame 24 bp insertion (c.428-451 dup (24 bp)), was identified in five patients. In one family, the mother of two affected boys was found not to carry the mutation detected in her sons. These data suggest the presence of germline mosaicism for the mutation in the mother. Our results confirm the significant contribution of ARX mutations in the etiology of MR, especially in this group of patients selected for XLMR (3%). These data, together with those reported in the literature, imply that screening for c.428-451 dup (24 bp) mutation should be recommended in all patients with suspected XLMR.

Adolescent↗

PubMed2002

Syndromic dystelephalangy.

We report an 8-year-old boy with a distinctive facial phenotype, deformities of fingers and toes and limitation of knee movement of unknown etiology. He had a round face, a long nose, a thin upper lip, a small mouth and micrognathia. In spite of microcephaly and retarded speech development secondary to hearing loss his mental development was within normal limits. The most distinctive radiographic abnormality was hypoplasia of the distal end of the middle phalanges with radial deviation of the distal phalanges.

Abnormalities, Multiple↗

PubMed2002

[Laboratory diagnosis of immunoglobulin deficiencies].

This review deals with the diagnostics of immunoglobulin defects. The development of methods used to detect and quantitate concentrations of immunoglobulins and their subclasses was shortly discussed; following by the role of antibodies in the host defence. Seven out of the ten main immunodeficiencies with the prevalence of antibody defects were then delineated. The diagnostics of humoral immunodeficiencies was illustrated by the example of three boys with hypogammaglobulinemia and three children with common variable immunodeficiency. Percentages of B lymphocytes varied, independent with the very decreased concentrations of immunoglobulin. Concentrations of IgG, IgA, IgM, IgE and IgG subclasses in healthy children of ages from birth to 16 years, were presented in the tables.

Adolescent↗