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Herein, we report mutation analysis of the LH receptor gene in 17 males with LH-independent precocious puberty, of which 8 were familial and 9 had a negative family history. A total of 7 different mutations (all previously reported) were detected in 12 patients. Among 10 European familial male-limited precocious puberty (FMPP) patients who had a LH receptor gene mutation, none had the Asp578Gly mutation, which is responsible for the vast majority of cases in the U.S. The restricted number of activating mutations of the LH receptor observed in this and other studies of FMPP strongly suggests that an activating phenotype is associated with very specific sites in the receptor protein. Clinical follow-up of the 5 patients who did not have LH receptor mutations shows that such cases most likely do not have true FMPP. LH receptor mutation analysis provides a sensitive tool for distinguishing true FMPP from other causes of early-onset LH-independent puberty in males.

Background: During skeletogenesis, protein levels of beta-catenin in the canonical Wnt signaling pathway determine lineage commitment of skeletal precursor cells to osteoblasts and chondrocytes. Adenomatous polyposis coli (Apc) is a key controller of beta-catenin turnover by down-regulating intracellular levels of beta-catenin. Results: To investigate whether Apc is involved in lineage commitment of skeletal precursor cells, we generated conditional knockout mice lacking functional Apc in Col2a1-expressing cells. In contrast to other models in which an oncogenic variant of beta-catenin was used, our approach resulted in the accumulation of wild type beta-catenin protein due to functional loss of Apc. Conditional homozygous Apc mutant mice died perinatally showing greatly impaired skeletogenesis. All endochondral bones were misshaped and lacked structural integrity. Lack of functional Apc resulted in a pleiotropic skeletal cell phenotype. The majority of the precursor cells lacking Apc failed to differentiate into chondrocytes or osteoblasts. However, skeletal precursor cells in the proximal ribs were able to escape the noxious effect of functional loss of Apc resulting in formation of highly active osteoblasts. Inactivation of Apc in chondrocytes was associated with dedifferentiation of these cells. Conclusion: Our data indicate that a tight Apc-mediated control of beta-catenin levels is essential for differentiation of skeletal precursors as well as for the maintenance of a chondrocytic phenotype in a spatio-temporal regulated manner.

To optimize the growth promoting effect of growth hormone (GH), 65 previously untreated girls with Turner syndrome (TS), chronological age (CA) 2-11 yr, were randomized into 3 dosage regimen groups: A, B, and C, with a daily recombinant-human GH dose during 4 study years of 4-4-4-4, 4-6-6-6, and 4-6-8-8 IU/m(2) b.s. The first GH dosage increase in groups B and C resulted in a significantly higher mean height velocity (HV) compared with constant dose group A. During the third year, when the dose was raised again only in group C, mean HV was significantly higher in groups B and C than in group A, and in group C compared with group B. In year 4 only group C mean HV remained significantly higher than group A. The pattern of change in HSDSCA (Dutch-Swedish-Danish Turner references) was identical; however, in year 4 mean Delta HSDSCA in group B also remained significantly higher than group A. After 4 yr GH treatment, the following was determined. 1) The mean Delta HSDSCA was significantly higher for groups B and C compared with group A, but not significantly different between groups B and C. 2) Although significantly higher compared with estimated values for untreated Dutch girls with TS, bone maturation of the GH treated girls was not significantly different between groups. 3) It was positively related with the degree of bone age (BA) retardation at start of study and negatively with baseline CA. 4) Both the modified Index of Potential Height (mIPH(RUS)) and a recently developed Turner-specific final height (FH) prediction method (PTSRUS), based on regression coefficients for H, CA, and bone age, showed significant increases in mean FH prediction, without significant differences between groups. PTSRUS values were markedly higher than the mIPH(RUS) values. Dose dependency could be shown for the area under the curve (AUC) for GH, but Delta HSDSCA was not linearly related with AUC. Baseline GH binding protein (BP) levels were in 84% of the cases within the normal age range; the decrease in mean levels after 6 months GH was not significant. Mean insulin-like growth factor I (IGF-I) and IGFBP-3 plasma levels increased significantly, without significant differences between groups. Delta HSDSCA during GH was dependent on IGF-I plasma levels at baseline and during the study period, beta-0.002 and beta-0.0004. Thus, a stepwise GH-dosing approach reduced the ''waning'' effect of the growth response after 4 yr treatment without undue bone maturation. FH prediction was not significantly different between treatment groups. Irrespective of the GH dose used, initiation of GH treatment at a younger age was beneficial after 4 yr GH when expressed as actual cm gained or as gain in FH prediction, but was not statistically significant when expressed as Delta HSDSCA over the study period.

The growth pattern of 28 girls and 32 boys with celiac disease was analyzed up to the ages of 10 and 12 years, respectively. Fifty-four patients (90%) were diagnosed before 4 years of age and six patients (10%) between 5 and 9 years of age. At diagnosis, 18 of 60 patients (30%) had a height SD score below -2.0, and 45 of 59 patients (76%) had a weight-for-height below the median. The mean height SD score showed increasing growth retardation in the year before diagnosis, relatively quick catch-up growth in the year after diagnosis, and complete catch-up in 2-3 years. Mean weight-for-height showed a progressive decrease 12-18 months before diagnosis, increased to a maximum at the end of the first year of therapy, and returned to normal 15 months after dietary treatment. Independent of age at diagnosis, initial degree of wasting, diagnostic delay, and strictness of gluten-free diet, catch-up growth was complete in this group of patients who were diagnosed before 9 years of age.

Girls with Turner syndrome were divided according to age (group A 6-12 years, and group B 12-19 years) and human growth hormone (GH) dose regimen (A1 and B1, three injections/week; A2 and B2, six injections/week). All groups responded to GH, 24 IU/M2/week, with an increase in height velocity, though in the older girls, the response was comparatively poor. Therefore, the dose regimens in groups B1 and B2 were increased to 36 IU/M2/week given as six injections in both groups. This change resulted in an increase in height velocity only in group B1. During the first 2 years only, the height velocity was greater in group A2 than group A1. The conclusion is that a regimen of six injections/week is more effective than one of three injections/week in terms of initial height gain and change in predicted adult height. In girls with Turner syndrome aged over 16 years, GH therapy has no significant effect.