1/5. Molecular cytogenetic characterization of a 10p14 deletion that includes the DGS2 region in a patient with multiple anomalies.We report on a prenatally diagnosed four-month-old boy with DiGeorge-like phenotype and a deletion of chromosome 10pter --> 14. fluorescence in situ hybridization (FISH) experiments using phage artificial chromosome (PAC) and yeast artificial chromosome (YAC) clones indicated that the chromosomal breakpoint was located at the proximal boundary of the digeorge syndrome 2 (DGS2) critical region. The patient demonstrated a high forehead, high arched eyebrows, short palpebral fissures, sparse eyelashes, prominent nose with bulbous tip, small mouth, receding chin, round ears with deficient helices, cardiac defects atrial septal defect (ASD), ventricular septal defect (VSD), mild brachytelephalangy, mild syndactyly, hypoplastic left kidney, undescended testes, muscular hypertonia, dorsally flexed big toes, and developmental delay. The phenotype corresponded well with the clinical signs of 10p deletion of this region that were described previously. The facial features appeared different from the typical face with the 22q11 deletion.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
2/5. 45X/46X,r(X) with syndactyly and severe mental retardation.Two white females, age 2 1/2 and 33 years, respectively, were investigated because of severe mental retardation associated with neurologic abnormalities, coarse face, and soft tissue syndactyly involving upper and lower limbs. Each had cytogenetic findings of a mosaic variant of Ullrich-turner syndrome with X ring chromosome in peripheral lymphocyte and skin fibroblasts. Early X replication occurred in one-third of the X ring chromosomes; there was no evidence for X-autosome translocation involving either X and an autosomal duplication; results of studies for fragility of the X chromosomes were unremarkable. in situ hybridization with an X centromere probe was positive for the ring. To our knowledge, the unusual constellation of cytogenetic, physical, and mental findings seen in these 2 individuals has not been reported previously.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
3/5. Keratin pattern of acanthosis nigricans in syndromelike association with polythelia, polycystic kidneys, and syndactyly.BACKGROUND: acanthosis nigricans (AN) comprises a broad spectrum of etiologic subtypes. The underlying pathomechanisms have not yet been completely clarified. We present a patient affected with a syndromelike AN subtype including disturbed epidermopoiesis as evidenced by immunohistologic findings and in situ hybridization. OBSERVATIONS: A 54-year-old white man contracted AN during childhood. There were connate malformations consisting of webbed toes II/III on the right side and a supernumerary left mammilla. As an adult he developed psoriasis vulgaris, obesity, and latent diabetes mellitus, polycystic kidney and liver disease. With regard to keratin 6 mRNA, and the protein expression of keratin 6/16, KI-67, and proliferating cell nuclear antigen, the AN lesion showed moderate hyperproliferation. A much higher degree of hyperproliferation was evident in psoriatic areas of the patient's skin. In contrast to psoriatic tissue, basal keratinocytes of the AN showed an unusually high expression of keratin 18 and 19 protein. CONCLUSIONS: The observation thus deals with a unique, syndromelike constellation of AN characterized by a particular epidermal pattern of moderate hyperproliferation. A further dysregulation of protein expression in the epidermis is indicated by the demonstration of the rare keratins 18 and 19 in basal keratinocytes of the AN lesion.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
4/5. Mental retardation and Ullrich-turner syndrome in cases with 45,X/46X, mar: additional support for the loss of the X-inactivation center hypothesis.Four cases having mosaicism for a small marker or ring [45,X/46,X, mar or 45,X/46,X, r] chromosome were ascertained following cytogenetic studies requested because of minor anomalies (cases 1, 3, and 4) and/or short stature (cases 2 and 4). While all 4 cases had traits typical of Ullrich-turner syndrome (UTS), cases 1, 3, and 4 had manifestations not usually present in UTS, including unusual facial appearance, mental retardation/developmental delay (MR/DD) (cases 3 and 4), and syndactylies (case 1). The facial appearances of cases 1 and 3 were similar yet distinct from that of case 4. Using fluorescence in situ hybridization (FISH), each of the markers in these 4 cases was identified as having been derived from an x chromosome. The level of mosaicism for the mar/r(X) cell line in these cases varied from 70% (case 1) to 16% (case 4) but was not apparently correlated with the presence of MR/DD. Replication studies demonstrated a probable early replication pattern for the mar/r(X) in cases 1, 3, and 4, while the marker in case 2 was apparently late replicating. To date, 41 individuals having mosaicism for a small mar/r(X) chromosome have been described. Interestingly, most of the 14 individuals having a presumedly active mar/r(X) demonstrated clinical findings atypical of UTS, including abnormal facial changes (11) and MR/DD (13). MR was noted most frequently in those cases having at least 50% mosaicism for the marker or ring. In contrast, atypical UTS facial appearance or MR/DD was not noted in 14 of the 16 cases with UTS who carried a probable late replicating marker or ring. In conclusion, although the phenotype of 45,X/46,X,mar/r(X) individuals appears to be influenced by the genetic content and degree of mosaicism for the mar/r(X), the most significant factor associated with MR/DD appears to be the activity status of the mar/r(X) chromosome. Thus, our 4 cases provide further support for the hypothesis that a lack of inactivation of a small mar/r(X) chromosome may be a factor leading to the MR and other phenotypic abnormalities seen in this subset of individuals having atypical UTS.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
5/5. Limb anomalies in DiGeorge and CHARGE syndromes.Limb anomalies are not common in the DiGeorge or CHARGE syndromes. We describe limb anomalies in two children, one with DiGeorge and the other with charge syndrome. Our first patient had a bifid left thumb, tetralogy of fallot, absent thymus, right facial palsy, and a reduced number of T-cells. A deletion of 22q11 was detected by fluorescence in situ hybridization (FISH). The second patient, with charge syndrome, had asymmetric findings that included right fifth finger clinodactyly, camptodactyly, tibial hemimelia and dimpling, and severe club-foot. The expanded spectrum of the DiGeorge and CHARGE syndromes includes limb anomalies.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |