Sarcoglycanopathies are among the most frequent and severe autosomal recessive forms of limb-girdle muscular dystrophies /LGMD/ with childhood onset. Mutations in , , and sarcoglycan genes lead to various kinds of LGMD. We present the clinical variability of LGMD 2C/R5 among a genetically homogeneous group of 56 patients, belonging to 35 pedigrees. Molecular genetic analysis showed thаt all 57 patients were homozygous for C283Y variant. The muscles of the pelvic girdle and the trunk were early and more severely affected, followed by the the shoulder girdle. Macroglossia, hypertrophy of the calves, scapular winging and lumbar hyperlordosis were common in the ambulatory phase. A great variability in the clinical presentation of LGMD 2C/R5 was observed both intra and interfamilial, despite the same underlying molecular defect. Females demonstrated a relatively milder clinical course, compared to males. Mean CK levels were 20 times above normal values. Muscle CT of MRI showed earlier and more severe involvement of the flexor proximal limb muscles in comparison to the extensor ones.

Introduction: Fragile X syndrome (FXS, OMIM #300624) is the most common inherited form of intellectual disability and the leading monogenic cause of autism. Aim: To present our experience with selective screening for FXS among high-risk children with intellectual disability/developmental delay/autistic behaviour and to further prove the importance of performing selective screening in a high-risk population.Materials and methods: Fifty-two children (45 boys and 7 girls) hospitalized in pediatric clinics or referred to genetic counseling services were tested with triplet repeat primed PCR based commercial kit. The mean age of participants was 6 years (the youngest was 2 years old, the oldest - 15 years old). These patients were selected based on the presence of at least one of the following clinical features: developmental delay, intellectual disability, and autistic-like behaviour.Results: All patients presented with developmental delay, including language delay. Intellectual disability and autistic-like behaviour were the most consistent features. Thirty-three children (63.4%) were with intellectual disability. Autism and autistic-like behaviour were observed in 22 patients (42.3%). Only 9 male patients (17.3%) presented with dysmorphic features typical for FXS. Three boys (5.7%) were found to be affected and two of their mothers - premutation carriers. Conclusions: The present study is the first attempt for molecular genetic selective screening for FXS among high-risk groups in north-eastern Bulgaria. Screening for FXS helps in making a definitive diagnosis along with providing genetic counseling to the family which includes reproductive planning and risk assessment.

Sarcoglycanopathies are among the most frequent and severe forms of autosomal recessive forms of limb-girdle muscular dystrophies (LGMDs) with childhood onset. Four subtypes are known: LGMDR3, LGMDR4, LGMDR5 and LGMDR6, which are caused, respectively, by mutations in the SGCA, SGCB, SGCG and SGCD genes. We present the clinical variability of LGMD 2C/R5 among a genetically homogeneous group of 57 patients, belonging to 35 pedigrees. Molecular genetic analysis showed that all 57 patients were homozygous for the C283Y variant. The muscles of the pelvic girdle and the trunk were affected early and were more severely affected, followed by the shoulder girdle. Macroglossia, hypertrophy of the calves, scapular winging and lumbar hyperlordosis were common in the ambulatory phase. A great intra and interfamilial variability in the clinical presentation of LGMD 2C/R5 was observed, despite having the same underlying molecular defect. Females demonstrated a relatively milder clinical course compared to males. Mean creatine phosphokinase (CK) CK levels were 20 times above normal values. Muscle computer tomography (CT) CT or MRIs showed earlier and more severe involvement of the flexor proximal limb muscles in comparison to extensor muscles.

Background: Anti-EGFR therapy, combined with chemotherapy, represents the standard therapeutic approach for triple wild-type (KRAS/NRAS and BRAF), left-sided, microsatellite stable (MSS) metastatic colorectal cancer (mCRC). However, acquired resistance develops in approximately 50% of patients. This study evaluated the efficacy of anti-EGFR therapy re-challenge and analyzed circulating tumor DNA (ctDNA) for potential resistance mechanisms. Methods: Eleven patients with triple wild-type, MSS, HER2-negative, left-sided mCRC were included. All patients received Cetuximab with chemotherapy as the first-line treatment, with three patients subsequently receiving Cetuximab re-challenge. Twenty-one plasma samples were collected at baseline and at each response assessment for retrospective ctDNA analysis using next-generation sequencing with a 16-gene panel. Results: Genetic alterations were detected in only 14.2% of ctDNA samples. In one re-challenge patient, the KRAS: c.35G>A mutation appeared during progression. No RAS mutations were identified in four patients who progressed on first-line Cetuximab treatment. Conclusions: This preliminary study suggests that clinically based anti-EGFR re-challenge may benefit selected mCRC patients. The low detection rate of resistance-conferring mutations indicates potential alternative resistance mechanisms beyond RAS pathway alterations. Our findings, while limited by sample size and the retrospective design of ctDNA testing, contribute to the growing evidence supporting anti-EGFR re-challenge strategies in mCRC management.