https://www.um.edu.mt/library/oar/handle/123456789/815 2026-05-26T11:33:28Z https://www.um.edu.mt/library/oar/handle/123456789/145981 Title: Bone fragility and osteoporosis in children and young adults Authors: Formosa, Melissa Marie; Christou, Maria A.; Mäkitie, Outi Abstract: Osteoporosis is a metabolic bone disorder which increases fragility fracture risk. Elderly individuals, especially postmenopausal women, are particularly susceptible to osteoporosis. Although rare, osteoporosis in children and young adults is becoming increasingly evident, highlighting the need for timely diagnosis, management and follow-up. Early-onset osteoporosis is defined as the presence of a low BMD (Z-score of ≤ −2.0 in individuals aged < 20 years; T-score of ≤ −2.5 in those aged between 20 to 50 years) accompanied by a clinically significant fracture history, or the presence of low-energy vertebral compression fractures even in the absence of osteoporosis. Affected children and young adults should undergo a thorough diagnostic workup, including collection of clinical history, radiography, biochemical investigation and possibly bone biopsy. Once secondary factors and comorbidities are excluded, genetic testing should be considered to determine the possibility of an underlying monogenic cause. Defects in genes related to type I collagen biosynthesis are the commonest contributors of primary osteoporosis, followed by loss-of-function variants in genes encoding key regulatory proteins of canonical WNT signalling (specifically LRP5 and WNT1), the actin-binding plastin-3 protein (encoded by PLS3) resulting in X-linked osteoporosis, and the more recent sphingomyelin synthase 2 (encoded by SGMS2) which is critical for signal transduction affecting sphingomyelin metabolism. Despite these discoveries, genetic causes and underlying mechanisms in early-onset osteoporosis remain largely unknown, and if no causal gene is identified, early-onset osteoporosis is deemed idiopathic. This calls for further research to unravel the molecular mechanisms driving early-onset osteoporosis that consequently will aid in patient management and individualised targeted therapy. 2024-01-01T00:00:00Z https://www.um.edu.mt/library/oar/handle/123456789/145948 Title: Idiopathic hypogonadotropic hypogonadism in the Maltese island population : a spectrum of phenotypes and genotypes Authors: Axiak, C.; Pleven, Adrian; Borg Carbott, Francesca; Attard, Ritienne; Cassar, Karen; Gruppetta, Mark; Vassallo, Josanne; Bezzina Wettinger, Stephanie; Farrugia, Rosienne Abstract: Idiopathic Hypogonadotropic Hypogonadism (IHH) is a rare, genetically heterogeneous infertility disorder characterized by absent or incomplete sexual maturation by age 18. This is due to a deficiency or absence of either pulsatile hypothalamic secretion of gonadotropin-releasing hormone (GnRH) and/or gonadotropins from the anterior pituitary in the presence of low serum sex steroids. IHH diagnosis is only conclusive if there are no other abnormalities to hypothalamic and pituitary morphology and function. 2021-01-01T00:00:00Z https://www.um.edu.mt/library/oar/handle/123456789/145917 Title: L-dopa responsive dystonia due to sepiapterin reductase deficiency, a tetrahydrobiopterin deficiency presenting without hyperphenylalaninaemia Authors: Farrugia, Rosienne; Scerri, Christian A.; Soler, D.; Parascandolo, Raymond; Felice, A. E. Abstract: Sepiapterin reductase (SPR) catalyses the last step in the biosynthesis of tetrahydrobiopterin (BH4), the essential cofactor for the aromatic amino acid hydroxylases as well as glycerol-ether monooxygenase and the three isoforms of nitric oxide synthase. The first patients with this disorder were diagnosed in the last two years. 2003-01-01T00:00:00Z https://www.um.edu.mt/library/oar/handle/123456789/145907 Title: Levels of Beta-thromboglobulin and platelet factor 4 are different between NSTEMI and STEMI : results from the MAMI Study Authors: Bonaci, J.; Attard, Ritienne; Dingli, Philip; Lisman, T.; Cassar, Karen; Doggen, C. J. M.; Bezzina Wettinger, Stephanie; Farrugia, Rosienne Abstract: Background: Platelet factor 4 (PF4) and Beta-Thromboglobulin (β-TG; NAP2) are both released from platelet a-granules during platelet ac tivation. The simultaneous measurement of both proteins in plasma may be a useful marker of platelet activation. 2017-01-01T00:00:00Z