Nikolinka Yordanova

Dr. Nikolinka Yordanova

orcid

Research Focus & Metrics

Academic Career Length

4Years (2023-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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2 February 2023 in Journal of Clinical Research in Pediatric Endocrinology
Verified
Journal Article
Open access
NYNikolinka Yordanova
Nikolinka Yordanova
VIVioleta Iotova
Violeta Iotova
DMD. J. G. Mackay
D. J. G. Mackay
ITI. K. Temple
I. K. Temple
SSS. Stoyanova
S. Stoyanova
Mari Ara HachmeriyanMari Ara Hachmeriyan
Mari Ara Hachmeriyan
Temple syndrome (TS) is a rare imprinting disorder, caused by alterations in the critical imprinted region 14q32 of chromosome 14. It is characterized by pre- and postnatal growth retardation, truncal hypotonia and facial dysmorphism in the neonatal period. We report a 18-year-old girl with a late diagnosis presenting all typical signs and symptoms of Temple syndrome - small for gestational age at birth, feeding difficulties, muscle hypotonia and delayed developmental milestones, central precocious puberty, truncal obesity and reduced growth. The patient is the second reported in the literature with signs of clinical and biochemical hyperandrogenism and the first treated with Dehydrocortisone®, with a good response. The clinical diagnosis of this patient was achieved after a long-term follow up at a single center of rare endocrine diseases, and a molecular genetics diagnosis of complete hypomethylation of 14q32 chromosome imprinting center (DLK/GTL2) was recently established. Growth hormone (GH) treatment was not given and although precocious puberty was treated in line with standard protocols, patient's final height remained below the target range. Increased awareness of Temple syndrome and timely molecular diagnosis enables improvement of clinical care of these patients as well as prevention of inherent metabolic consequences.

16 December 2025 in Preprints.org
Verified
Preprint
Open access
PDF file
SASimona Anzhel
Simona Anzhel
NYNikolinka Yordanova
Nikolinka Yordanova
EKEmil Kovachev
Emil Kovachev
DKDarina Krumova
Darina Krumova
EIElis Ismail
Elis Ismail
Background: Prader-Willi syndrome (PWS) is a multisystemic complex imprinting disorder. Prenatal diagnosis of PWS is still a challenge with non-specific ultrasound markers and limitations for diagnosis with non-invasive screening methods. Prenatal suspicion and early postnatal diagnosis are mandatory for promoting healthy growth and development, preventing complications, and providing health care professionals and families with the necessary support and resources for effective management. Presentation: We report two PWS cases caused by maternal uniparental disomy, who presented with IUGR, specifically reduced fetal abdominal circumference (AC) during the second and early third trimesters against the background of reduced fetal move-ments, normal Doppler indicators and oligohydramnios. They were diagnosed in the early neonatal period with no prenatal suspicion but with similar ultrasound markers of the developing pregnancies, analyzed retrospectively. Aim: The aim of this study is to emphasise the need to raise awareness among specialists about genetic syndromes such as Prader–Willi syndrome, in order to improve the information provided to couples regarding the limitations of current prenatal screening methods, as well as to ensure that, in cases of prenatal suspicion, appropriate genetic testing can be initiated. A confirmed diagnosis would allow timely and adequate measures to be taken, given the complications of the postnatal period in these patients and their need for specialised care and management Conclusions: The presence of the aforementioned prenatal characteristics may raise suspicion for PWS. In such cases, invasive diagnostic procedures and methylation testing may be indicated, enabling earlier diagnosis and timely management, which can ultimately improve the quality of life of affected individuals and their families.

28 January 2026 in Children
Verified
Journal Article
Open access
PDF file
SASimona Anzhel
Simona Anzhel
NYNikolinka Yordanova
Nikolinka Yordanova
EKEmil Kovachev
Emil Kovachev
DKDarina Krumova
Darina Krumova
EIElis Hudaim Ismail
Elis Hudaim Ismail
Background: Prader–Willi syndrome (PWS) is a multisystemic complex imprinting disorder. Prenatal diagnosis of PWS is still a challenge with non-specific ultrasound markers and limitations for diagnosis with non-invasive screening methods. Prenatal suspicion and early postnatal diagnosis are essential for promoting healthy growth and development, preventing complications, and providing healthcare professionals and families with the necessary support and resources for effective management. Presentation: We report two PWS cases caused by maternal uniparental disomy, who presented with IUGR, characterized by reduced fetal abdominal circumference (AC) in the second and early third trimesters, reduced fetal movements, normal Doppler indices and oligohydramnios. They were diagnosed in the early neonatal period with no prenatal suspicion but with similar ultrasound markers of the developing pregnancies, analyzed retrospectively. Aim: This study aims to emphasize the need to raise awareness among specialists about genetic syndromes such as Prader–Willi syndrome, to improve the information provided to couples regarding the limitations of current prenatal screening methods, as well as to ensure that, in cases of prenatal suspicion, appropriate genetic testing can be initiated. A confirmed diagnosis would allow timely and adequate measures to be taken, given the complications of the postnatal period in these patients and their need for specialized care and management. Conclusions: The presence of the aforementioned prenatal characteristics may raise suspicion for PWS. In such cases, invasive diagnostic procedures and methylation testing may be indicated, enabling earlier diagnosis and timely management, which can ultimately improve the quality of life of affected individuals and their families.

5 May 2026 in BMC Endocrine Disorders
Verified
Journal Article
Open access
NYNikolinka Yordanova
Nikolinka Yordanova
MVMila Vasileva
Mila Vasileva
SGSonya Galcheva
Sonya Galcheva
VIVioleta Iotova
Violeta Iotova
Prader-Willi syndrome (PWS) is a rare imprinting disorder characterized by typical dysmorphic features, lack of satiety, infantile hypotonia, and later morbid obesity with complications, short stature, hypogonadotropic hypogonadism, skeletal and psychiatric problems. From the literature, it is well known that patients with PWS have a more favorable metabolic pattern than healthy controls. The aim of the study is to assess the metabolic profile of PWS patients followed at an Expert Center for Rare Endocrine Diseases compared with healthy controls and to look for relations between components of the metabolic syndrome (MetS), adipokines, and the compartments of body composition (BC-lean and fat mass). The current study is a cross-sectional evaluation of 25 patients with Prader-Willi syndrome (mean age 11.3 ± 8.2 years), with a total of 183.6 patient-years of regular follow-up (from the first visit to the center to the data collection cutoff date), compared with 24 age-, sex-, and BMI-matched healthy controls (mean age 11.3 ± 3.9 years). Each participant underwent anthropometric measurements, physical examination, biochemical and hormonal blood sampling, and whole-body DXA scan. Statistical analysis (SPSS 15.0 statistical package, Chicago, IL, USA) was performed to assess the relations between the metrics in the PWS group compared with controls. Patients with PWS showed a better profile of glucose homeostasis with significantly lower serum insulin concentration and calculated HOMA-IR index compared with the controls (p < 0.05). Taking into consideration age, sex, and body mass index (BMI) in the PWS group, the analysis showed strong positive correlations between waist circumference (WC) and systolic blood pressure (SBP) (r = 0.864, p < 0.001), and WC and diastolic blood pressure (DBP) (r = 0.534, p = 0.033). Partial correlation analysis with respect to age, sex, and pubertal development found significant positive WC correlations with insulin (r = 0.796, p = 0.006), HOMA-IR (r = 0.697, p = 0.025), LDL-cholesterol (r = 0.735, p = 0.002), uric acid (r = 0.735, p = 0.002), CRP (r = 0.600, p = 0.023), and leptin (r = 0.730, p = 0.005). Strong negative correlations existed between WC and SHBG (r = -0.772, p = 0.002) and HMW adiponectin (r = -0.998, p = 0.044). Additionally, a negative correlation of HMW adiponectin and SBP was demonstrated. 88% of the patients were treated with recombinant human growth hormone (rhGH). Bone mineral density adjusted for height (BMD/height) was significantly lower in patients with PWS (p < 0.05) compared with healthy controls. The analysis did not reveal significant relationships between BC compartments and metabolic and auxological parameters in the PWS group. Our study confirms that patients with PWS have a favorable metabolic profile compared with healthy controls matched by age, sex, and BMI. Syndromic participants who manifest greater accumulation of abdominal adipose tissue have a higher risk of hemodynamic changes and metabolic disturbances predictive of the development of cardiovascular diseases (CVD) in adulthood. WC could serve as a predictive marker for detecting higher metabolic risk in this syndromic group of patients, and both WC and HMW adiponectin for hypertension. In the future, on this basis, we could possibly implement both of these metrics in clinical practice.