Ulrich K. Bühler

Diurnal rhythm in total serum thyroxine levels.

The diurnal variation of serum thyroxine, plasma proteins, and hematocrit were studied in six patients (euthyroid, hypothyroid, and thyrotoxic) and in two obese subjects during total fast. Variations of 7% to 34% were observed in serum total protein, hematocrit, protein-bound iodine, total thyroxine, thyroxine binding globulin, and prealbumin binding capacity, and thyroxine dialyzable fraction, but not in the concentration of serum free thyroxine. Similar and parallel diurnal variation was observed during studies of the disappearance of 131 I-labeled thyroxine and 125 I-labeled albumin. The maximal daily concentration occurred between 10:00 a.m. and 2:00 p.m., and the minimum occurred around 2:00 a.m. These diurnal variations were not related to food intake or adrenocortical function but were influenced by posture. A reversed cyclic change could be produced by reversing the normal sleep-waking pattern. Because of reciprocal changes in the concentration of total serum thyroxine and thyroxine dialyzable fraction, the serum-free thyroxine concentration remained constant. These rhythmic changes are apparently caused by movement of fluid into and out of the vascular compartment. This factor may be an important cause of scatter in the observations recorded during studies of slowly diffusible plasma constituents if repeated blood sampling is not performed under the same conditions.

Chromosome deletion and multiple cartilaginous exostoses.

We report a 13 year-old girl with manifestations strikingly reminiscent of the tricho-rhino-phalangeal (TRP) II or Langer-Giedion syndrome. A terminal deletion of 8q must be assumed to be the cause of her condition till proven otherwise. A similar chromosome abnormality should be searched for (blindly) in other cases of the TRP II previously thought to have had normal chromosomes.

Terminal or interstitial deletion in chromosome 8 long arm in Langer-Giedion syndrome (TRP II syndrome)?

SummaryReexamination with high resolution banding of the first ever published case of Langer-Giedion syndrome with 8q deletion as well as chromosome examination of a second case of this syndrome with different high resolution methods, confirmed our previous assumption of a terminal 8q involvement in the causation of TRP II syndrome.

Non-Condensation of One Segment of a Chromosome No. 2 in a Male with an Otherwise Normal Karyotype (and Severe Hypospadias)

SummaryA child with severe hypospadias is presented, whose karyotype showed in about 11% of mitoses of peripheral blood one member of chromosome pair No. 2 with a non-condensed region near the centromere. The non-condensed segment does not show late replication, however, it is situated very close to the late replicating segment of the long arms of chromosome No. 2. The nature and possible implications of this kind of aberration are discussed. It is held that non-condensation can produce localized chromosome breaks by a mechanism possibly different from any of the classical breakage mechanisms.

Familiäres Mosaik mit G-ring

SummaryA family with G-ring mosaicism in two generations in presented. The index patient has the chromosome constitution: G-ring / G-monosomy. His mother, brother and maternal uncle are mosaics with 3 cell lines: Normal (predominantly) / G-ring (few) / G-monosomy (few). The index patient presents with small stature (below 3rd percentile) and mental retardation, his mother, brother and uncle are clinically normal individuals except for some minor degenerative signs. The lack of similarity between the phenotypes of the index patient and of other carriers of a G-ring from the literature does not seem to justify the assertion of a new syndrome.ZusammenfassungDas familiäre Vorkommen eines G-Rings in Mosaikkonstitution zweier Generationen wird beschrieben. Der Proband stellt ein Mosaik mit der Formel G-Ring/G-Monosomie dar. Seine Mutter, Bruder und Onkel mütterlicherseits sind Mosaikkonstitutionen mitden Zellinien: Normal (überwiegend) / G-Ring (schwach) / G-Monosomie (schwach). Der Proband ist geistig retardiert und klein gewachsen (unter der 3. Perzentile), die übrigen Mosaikindividuen sind bis auf wenige pathologische Züge klinisch unauffällig. Der Merkmalsvergleich zwischen dem Probanden und den anderen, in der Literatur beschriebenen Fällen von G-Ring-Trägern zeigt, daß die Phänotypen dieser Individuen jene Ähnlichkeiten vermissen lassen, welche die Aufstellung eines Syndroms rechtfertigen würden.

Possible role of heterochromatin in human aneuploidy

It is assumed that late replicating allocyclic segments of human autosomes consist mainly of heterochromatin and might1)originate in euchromatin at an early embryonic state2)promote non-disjunction of the corresponding chromosome during an early embryonic mitosis by delaying chromatide separation3)permit survival of the resulting aneuploidy owing to the relative genetic inertness of heterochromatin.

45,X/46,XYq dic-Geschlechtschromosomenmosaik

SummaryThis is the report on an obese girl with small stature and sexual infantilism. A 45,X/46,XYq dic mosaic was found in blood and fibroblast cultures. A summary is given of the cases so far reported in the literature. The clinical picture does not differ significantly from that of 45,X/46,XY cases. The relationship of phenotype and structural abnormalities of the Y chromosome is discussed.ZusammenfassungEs wird über eine Patientin mit Kleinwuchs, Adipositas und sexuellem Infantilismus berichtet. Die Abklärung ergab ein 45,X/46,XYq dic-Mosaik. Es folgt eine Zusammenfassung der bis jetzt in der Literatur beschriebenen Fälle von Ydic. Das klinische Bild unterscheidet sich nicht wesentlich von jenem des 45,X/46,XY-Mosaiks. Anschließend werden die Zusammenhänge zwischen strukturellen Aberrationen des Y-Chromosoms und Phänotypus diskutiert.