Linkage studies in X-linked Alport's syndrome

Summary Four kindreds segregating for Alport's syndrome (ASLN) compatible with a X-linked inheritance were studied for linkage with polymorphic markers of the human X chromosome. No recombinant was observed between the ASLN locus and the DXS101 and DXS94 loci, the maximum lod scores were z=3.93 and 3.50 respectively. Linkage data between the ASLN locus and the other genetic markers used in the present study are in keeping with the assignment of the mutation to the proximal Xq arm.     

Laurence-Moon-Biedl syndrome in presumably identical twins

Summary A Saudi Arabian family with 3 cases of Laurence-Moon-Biedl syndrome, 2 of whom are presumably identical twins, is presented. Although it is generally accepted that this condition is inherited as an autosomal recessive trait, no conclusive data exist in the literature to support this theory.

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Zusammenfassung Wir präsentieren eine saudiarabische Familie, in der 2 Mitglieder vermutlich eineiige Zwillinge sind. In dieser Familie finden sich 3 Fälle von Laurence-Moon-Biedl-Syndrom. Wenngleich allgemein angenommen wird, daß dieser Zustand als autosomales recessives Merkmal vererbt wird, existieren hierfür keine überzeugenden Daten in der Literatur.

     

Hematologic chimerism in cattle twins]

A cytogenetic examination of a cow and its offsprings, obtained by pair transplantations of the embryos was carried out. The fragile X and the heteromorphism of the chromosomes XX of this cow and some of its offsprings were revealed. The variability of the hematological chimerism of the pair transplanted embryos was observed. The immigrated cells were, as a rule, distinguished by the comparatively low frequencies of the metaphases with the nearly located chromosomes XX. The heterogeneity of the stem blood cells of the embryos for some traits, and for the ability to migrate in the blood of the twin is under discussion.     

Ring chromosome 14 in monozygotic twins]

An r(14) is observed in monozygotic twins, with psychomotor retardation and no obvious somatic malformation.     

Monozygotic twins concordant for Kleine-Levin syndrome

ABSTRACT: BACKGROUND: Kleine-Levin syndrome is a rare idiopathic form of episodic hypersomnia that typically occurs during adolescence. The cardinal clinical features are recurrent hypersomnia, accompanied by cognitive disturbances and behavioral abnormalities [1]. The most typical form of classical Kleine-Levin syndrome is associated with hyperphagia [2, 3], although hyperphagia is now optional after change of the criteria. Hypersexuality, behavioral disinhibition, delusions, autonomic alteration and hallucinations have also been described, but the patients show normal cognitive function and behavior between attacks. The pathogenesis of Kleine-Levin syndrome is not yet known. Although most cases of recurrent hypersomnia are sporadic, the occurrence of nine familial cases indicate that there may be a genetic predisposition to the syndrome [4-8] However, no cases of twins affected with Kleine-Levin syndrome have been reported [9]. In this case study we describe monozygotic twins suffering from the syndrome. This is the first case report describing twins affected with Kleine-Levin syndrome thereby supporting the theory that there is an underlying genetic predisposition to the syndrome.     

Down's syndrome in twins with discordant HL-A phenotypes

Summary A male twin pair discordant in morphological characteristics and HL-A phenotype but concordant in trisomy 21 and the blood group markers is reported.The coincidental occurrence of two rare conditions (nondisjunction and dizygotic twinning) and a high probability of monozygosity (inferred from the blood group findings) gave rise to the question of whether the boys might represent intermediates between dizygotic and monzygotic twins. Postcleavage fertilization can be excluded as a circumstance leading to intermediates since the twins have different maternal HL-A haplotypes.

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Zusammenfassung Ein männliches Zwillingspaar wird vorgestellt, das in einigen morphologischen Merkmalen und im HL-A-Phänotypus diskordant, hinsichtlich einer Trisomie 21 und der Blutgruppenmerkmale aber konkordant ist.Auf Grund des Zusammentreffens zweier seltener Ereignisse (nondisjunction und Zweieiigkeit), insbesondere aber auch wegen starker blutgruppenserologischer Hinweiswahrscheinlichkeiten für Eineiigkeit, wird die Frage gestellt, ob die Knaben möglicherweise eine intermediäre Position zwischen Eineiigkeit und Zweieiigkeit einnehmen. Von den Möglichkeiten, die zu einer solchen Zwischenstellung führen könnten, scheidet die einer Befruchtung des Eies erst nach der Furchung aus, da beide Zwillingspartner unterschiedliche mütterliche HI-A-Haplotypen aufweisen.

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Supported by the Deutsche Forschungsgemeinschaft.     

Basic properties of nervous processes in twins]

Characteristics of nervous processes were studied in 50 pairs of twins by the verbal motor method with a preliminary verbal instruction. A chronographic reflexmeter with programmed control was used. Statistical processing of the data and calculation of heredity coefficients by the Holsinger formula has shown that the average intrapair difference in monozygotic twins (MT) was, as a rule, smaller than in dizygotics (DT). Dispersion analysis revealed a considerable dispersion of resultative characters in DT as compared with MT. The heredity coefficients obtained for the strength of the inhibitory process (H=0.88), that of the excitatory process (H=0.50), the mobility of nervous processes (H=0.42) and the rate of conditioning (H=0.34) points to a considerable genotypic determination of the examined properties of nervous processes.     

Skeletal development in monozygotic and dizygotic twins]

The maturation and development of 27 monozygotic and 23 dizygotic twins were studied over a 10 year period with data collected at one year intervals from age 9 to adulthood. In this manner the ossification process was recorded based on X-ray films of the carpal bones. Further information was acquired through anthropometric and somatoscopic data reproduced with standard photography. Sex and phase specific genetic factors influencing the maturation process are presented and analysed.     

The type of higher nervous activity in twins]

Exmination of twelve pairs of monozygote (MT) and dizygote (DT) twins and their control groups revealed an identity of the higher nervous activity type and a high positive intrapair and group correlation of typological parameters in MT (0.42); a predominantly different typological classification and a lower correlation in DT (0.33); a low correlation in the control group No. 1 and mere traces of general positive correlation in group No. 2 (0.07) and No. 3. The data point to the considerable genetic dependence of the higher nervous activity type; they also serve as a verification of the method used.     

Folic acid blinded trial in identical twins with fragile X syndrome.

Monozygous twin 14-year-old mentally retarded boys with the fragile X syndrome were treated either with 10 mg folic acid by mouth daily or with a placebo for three test periods of 3-month duration each in a blind study. For each twin, tests of cognitive functioning, reading, spelling, and math skills, and linguistic and perceptual skills were compared. Although there was considerable variation in performance on these tests during the two baseline periods, there were no observable beneficial effects of therapy. The routine use of folic acid in patients with established mental retardation and the fragile X syndrome is not indicated.     

Glomerular morphometry in biopsy evaluation of minimal change disease, membranous glomerulonephritis, thin basement membrane disease and Alport's syndrome

OBJECTIVE: To assess the role of glomerular morphometry in biopsy evaluation in renal disorders in addition to conventional diagnostic procedures. STUDY DESIGN: The study includes 10 cases each of minimal change disease (MCD), idiopathic membranous glomerulonephritis (idiopathic MGN), thin basement membrane disease (TBMD) and Alport's syndrome. Renal biopsies for normal study were obtained from age- and sex-matched autopsy cases without any renal disorder, confirmed histologically and ultrastructurally. Glomerular morphometry was performed by semiautomatic procedure using Quantimet-600 image analysis system (Leica, Cambridge, United Kingdom). RESULTS: Morphometric findings revealed significant increase in glomerular "diameter and area" and "tuft diameter and area" in patients of idiopathic MGN, but no significant difference was found in patients of MCD, TBMD and Alport's syndrome. Evaluation of glomerular volume fractions revealed a decrease in capillary space volume fraction and an increase in "membranes and mesangial matrix" volume fraction in patients with idiopathic MGN. Significant decrease in capillary space volume fraction was also observed in patients of MCD. Patients with Alport's syndrome showed variable changes. CONCLUSION: Glomerular morphometry could be considered as an adjunct to the diagnostic armamentarium of light microscopy, immunofluorescence and electron microscopy because it provides deep insight into quantitative parameters.     

Stress-age syndrome]

Aging is accompanied by occurrence of a set of neurohormonal, tissue and cellular changes, which can be defined as stress-age-syndrome. One group of components of the above syndrome is of adaptive importance, while the other--of damaging one. Symptoms of stress-age syndrome have their individual peculiarities and cannot explain the whole complexity of symptoms of the organism aging.