Basal body temperature curves and endocrine pattern of menstrual cycles in Down syndrome

RUN(X) out of blood: emerging RUNX1 functions beyond hematopoiesis and links to Down syndrome

BACKGROUND

RUNX1 is a transcription factor and a master regulator for the specification of the hematopoietic lineage during embryogenesis and postnatal megakaryopoiesis. Mutations and rearrangements on RUNX1 are key drivers of hematological malignancies. In humans, this gene is localized to the 'Down syndrome critical region' of chromosome 21, triplication of which is necessary and sufficient for most phenotypes that characterize Trisomy 21.

MAIN BODY

Individuals with Down syndrome show a higher predisposition to leukemias. Hence, RUNX1 overexpression was initially proposed as a critical player on Down syndrome-associated leukemogenesis. Less is known about the functions of RUNX1 in other tissues and organs, although growing reports show important implications in development or homeostasis of neural tissues, muscle, heart, bone, ovary, or the endothelium, among others. Even less is understood about the consequences on these tissues of RUNX1 gene dosage alterations in the context of Down syndrome. In this review, we summarize the current knowledge on RUNX1 activities outside blood/leukemia, while suggesting for the first time their potential relation to specific Trisomy 21 co-occurring conditions.

CONCLUSION

Our concise review on the emerging RUNX1 roles in different tissues outside the hematopoietic context provides a number of well-funded hypotheses that will open new research avenues toward a better understanding of RUNX1-mediated transcription in health and disease, contributing to novel potential diagnostic and therapeutic strategies for Down syndrome-associated conditions.

Low AMH levels as a marker of reduced ovarian reserve in young women affected by Down's syndrome

OBJECTIVE

Women with Down's syndrome (DS) experience menopause earlier than healthy women and are twice as likely to undergo premature ovarian insufficiency. Menopause accelerates cognitive decline and is associated with a twofold increased mortality risk in DS women. Nonetheless, no previous studies investigated the ovarian reserve in this population. The aim of the present study was to evaluate the circulating antimullerian hormone (AMH) levels in DS women with regular menstrual cycles, in comparison with those observed in an age-matched group of healthy women.

METHODS

Fourteen women with DS and 20 normo-ovulatory volunteers were enrolled in this study. A general physical examination was performed. Hormonal assays, including AMH, fasting insulin levels, and homeostatic model assessment-insulin resistance, were investigated in all participants.

RESULTS

AMH levels were significantly lower in DS women compared with controls (1.34 ± 1.11 vs 3.01 ± 1.65 ng/mL, P < 0.01). Prolactin concentrations were in the normal range, although higher in DS women compared with controls (P < 0.01). After dividing the participants according to age, AMH was significantly lower in the DS group compared with controls, both below and above 30 years of age (1.77 vs 3.73 ng/mL, P < 0.01; 0.28 vs 2.20 ng/mL, P < 0.01, respectively). AMH was inversely correlated with age in both groups, and directly correlated with testosterone and dehydroepiandrosterone sulfate only in DS women. In the same participants, AMH showed a tendency toward a direct correlation with insulin levels (P = 0.055).

CONCLUSIONS

AMH levels were significantly lower in DS women compared with age-matched controls. A subanalysis of data in DS participants under 30 years of age suggested an early follicular depletion related to trisomy 21.

Menstrual profile and early menopause in women with Down syndrome aged 26-40 years

BACKGROUND

It is known that women with Down syndrome can be fertile, but it is not known whether all women with Down syndrome are fertile or sub-fertile. The age at menopause for women with Down syndrome is lower compared to women without Down syndrome.

METHOD

A cross-sectional study of 11 women was undertaken, in which the participating women had a blood sample taken and were also examined using transabdominal ultrasound scanning (ULS).

RESULTS

Definite signs of ovulation were evident in 2 women; hormone values in 5 women showed that they were in the luteal phase of the menstrual cycle; 1 woman was anovulatory; and in 1 woman it was not possible to judge the time of the menstrual cycle. Two of the women were postmenopausal according to medical information, ultrasound examination and hormone values.

CONCLUSIONS

Safe contraceptives should be considered and offered if women with Down syndrome are engaging in sexual relations. Early menopause (before the age of 40 years) and the possibility of hormonal replacement therapy should be kept in mind.

Beta-adrenergic hyperresponsiveness in compensated hypothyroidism associated with Down syndrome

Although compensated hypothyroidism (CH) is the most common thyroid impairment in Down syndrome (DS), its pathogenesis remains elusive. Because primary gonadal failure is another DS-associated endocrinopathy, we hypothesized that an impaired signal-transduction pathway shared by several organs may provide a unifying explanation for both endocrinopathies. We assessed two possible transduction-pathway components associated with CH in DS: the G-protein adenylate-cyclase (AC) system and beta-adrenergic responsiveness, previously reported to be enhanced in DS fibroblasts. Twenty-one DS patients and 14 control subjects were studied. Peripheral mononuclear cells (PMCs) were incubated with G-protein modulators [prostaglandin E1 (PGE1) and cholera toxin (CTx)], an AC stimulator (forskolin), and a beta-adrenergic agonist (isoproterenol), and cAMP levels were determined. All participants had normal plasma thyroid hormone levels, but 11 of the DS patients had elevated TSH levels (hTSH), whereas in the 10 others, they were normal (nTSH). cAMP levels in response to forskolin, PGE1, and CTx were similar in all groups, whereas isoproterenol-stimulated cAMP levels were significantly higher in the hTSH group than in the nTSH group and control subjects (45 +/- 30 versus 22 +/- 9 and 21 +/- 9 pmol . 10(6) cells(-1) . 10 min(-1), respectively; p = 0.02). Four patients in the DS hTSH subgroup had impaired sexual development. We found hyperresponsiveness of PMCs to a beta-adrenergic agonist in a subgroup of DS patients with CH. If this observation is applicable to the thyroid gland, then it may reflect a mechanism in which negative effects on cell growth or responsiveness to TSH lead to CH.

Growth hormone administration normalizes the ovarian responsiveness to follicle-stimulating-hormone in the early stages of the follicular maturation in women with Down syndrome

To investigate the sensitivity of ovary to follicle-stimulating hormone (FSH) during the early follicular phase of the human menstrual cycle in patients with Down Syndrome (DS) six postmenarchal patients with Down Syndrome and twelve normoovulatory women were studied. Randomly, DS patients were submitted in two consecutive cycles to a treatment with GH (0.1 IU/Kg i.m.) or saline for 3 days. Pure FSH (75 IU) was given i.v. at day 3 and plasma levels of LH, FSH, E2, Testosterone, DHEAS, Androstenedione, GH and IGF-I were assayed in samples collected for a period of 26 h after the injection. Data were compared with those obtained from controls receiving pure FSH or saline. In control patients FSH injection increased E2 stimulated area under curve (AUC). This value was significantly greater than that found in DS patients, who exhibited an E2-stimulated AUC superimposable to saline treated controls. In DS GH plasma concentrations were significantly lower than in control group (p < 0.05). The treatment with GH is able to normalize the ovarian response to FSH in DS patients at levels similar to those found in FSH treated controls. Moreover in GH treated cycles, both GH and IGF-I plasma concentrations were higher at time of FSH injection with respect to those found in the cycles where saline was given. These results indicate that the ovarian sensitivity to FSH in patients with DS is blunted. Lower GH plasma levels found in this group may in part account for this biological feature, since GH treatment is able to restore the ovarian response, probably via an increase of IGF-I plasma concentrations.

A history of miscarriages and mild prognathism as possible mode of presentation of mosaic trisomy 18 in women

A 22-year-old woman seeking medical assistance for hypofertility after two miscarriages had very slight anomalies: mild macrogenia and prognathism, and temporal depilation. Peripheral lymphocytes and fibroblastic karyotypes disclosed the tenth published case of low-level mosaicism for trisomy 18 with normal intelligence. Subfertility is frequently observed among these patients. As women with this anomaly are at risk of trisomy 18 pregnancies and as five cases have been reported recently, this particular chromosomal anomaly may not be so exceptional and should be investigated in cases of hypofertility.