Browsing by Author "Sarajlija, A. (26027638400)"

Deficiency of lysosomal acid lipase (LAL-D) is caused by biallelic pathogenic variants in the LIPA gene. Spectrum of LAL-D ranges from early onset of hepatosplenomegaly and psychomotor regression (Wolman disease) to a more chronic course (cholesteryl ester storage disease - CESD). The diagnosis is based on lipid and biomarker profiles, specific liver histopathology, enzyme deficiency, and identification of causative genetic variants. Biomarker findings are a useful for diagnostics of LAL-D, including high plasma concentration of chitotriosidase as well as elevated oxysterols. Current treatment options include enzyme replacement therapy (sebelipase-alpha), statins, liver transplantation, and stem cell transplantation. We present two pairs of siblings from Serbia with a distinctive phenotype resembling LAL-D with a novel variant of unknown significance (VUS) detected in the LIPA gene and residual LAL activity. All patients presented with hepatosplenomegaly at early childhood. In siblings from family 1, compound heterozygosity for a pathogenic c.419G>A (p.Trp140Ter) variant and a novel VUS c.851C>T (p.Ser284Phe) was detected. Patients from family 2 were homozygous for c.851C>T VUS and both have typical histopathologic findings for LAL-D in the liver. Enzyme activity of LAL was tested in three patients and reported as sufficient, and therefore enzyme replacement therapy could not be approved. When confronted with a challenge of diagnosing an inherited metabolic disorder, several aspects are taken into consideration: clinical manifestations, specific biomarkers, enzyme assay results, and molecular genetic findings. This report brings cases to light which have a considerable discrepancy between those aspects, namely the preserved LAL enzyme activity in presence of clinical manifestations and rare variants in the LIPA gene. © 2022 Sarajlija A., Armengol L., Maver A., Kitic I., Prokic D., Cehic M., Djuricic M.S., Peterlin B., published by Sciendo.

Deficiency of lysosomal acid lipase (LAL-D) is caused by biallelic pathogenic variants in the LIPA gene. Spectrum of LAL-D ranges from early onset of hepatosplenomegaly and psychomotor regression (Wolman disease) to a more chronic course (cholesteryl ester storage disease - CESD). The diagnosis is based on lipid and biomarker profiles, specific liver histopathology, enzyme deficiency, and identification of causative genetic variants. Biomarker findings are a useful for diagnostics of LAL-D, including high plasma concentration of chitotriosidase as well as elevated oxysterols. Current treatment options include enzyme replacement therapy (sebelipase-alpha), statins, liver transplantation, and stem cell transplantation. We present two pairs of siblings from Serbia with a distinctive phenotype resembling LAL-D with a novel variant of unknown significance (VUS) detected in the LIPA gene and residual LAL activity. All patients presented with hepatosplenomegaly at early childhood. In siblings from family 1, compound heterozygosity for a pathogenic c.419G>A (p.Trp140Ter) variant and a novel VUS c.851C>T (p.Ser284Phe) was detected. Patients from family 2 were homozygous for c.851C>T VUS and both have typical histopathologic findings for LAL-D in the liver. Enzyme activity of LAL was tested in three patients and reported as sufficient, and therefore enzyme replacement therapy could not be approved. When confronted with a challenge of diagnosing an inherited metabolic disorder, several aspects are taken into consideration: clinical manifestations, specific biomarkers, enzyme assay results, and molecular genetic findings. This report brings cases to light which have a considerable discrepancy between those aspects, namely the preserved LAL enzyme activity in presence of clinical manifestations and rare variants in the LIPA gene. © 2022 Sarajlija A., Armengol L., Maver A., Kitic I., Prokic D., Cehic M., Djuricic M.S., Peterlin B., published by Sciendo.

Introduction. Disorders of sexual development can present isolated or as a part of complex genetic syndromes. Case presentation. A newborn with ambiguous genitalia and prenatally diagnosed brain malformations was referred to our hospital. Prenatal ultrasound examination and MRI showed lissencephaly and absence of the corpus callosum. At admission, physical examination revealed microphallus, hypospadia and complete fusion of labioscrotal folds with nonpalpable gonads, normal blood pressure and serum biochemistry. Cortisol level was normal (201 nmol/L), testosterone elevated (14.4 nmol/L), FSH 0.1 IU/L, LH 0.7 IU/L, estradiol 241 pmol/L. Seizures were noted on the 2nd day and the child was started on anticonvulsives. When 17-OHP level results came back elevated (200 nmol/L), ACTH test was performed and the child was started on hydrocortisone and fludrocortisone treatment. Congenital adrenal hyperplasia became unlikely when karyotype result showed normal male karyotype (46, XY, SRY+) with no Mullerian structures seen on ultrasonographic exam. As association of ambiguous genitalia and lissencephaly strongly suggested a mutual genetic background, diagnosis of X-linked lissencephaly with ambiguous genitalia (X-LAG) became apparent. Conclusions. The presented case highlights the importance of looking at the whole clinical picture instead of separate isolated findings with emphasis on patient-centered approach guided by clinical findings and patient history. © 2021, Acta Endocrinologica Foundation. All rights reserved.

Introduction. Disorders of sexual development can present isolated or as a part of complex genetic syndromes. Case presentation. A newborn with ambiguous genitalia and prenatally diagnosed brain malformations was referred to our hospital. Prenatal ultrasound examination and MRI showed lissencephaly and absence of the corpus callosum. At admission, physical examination revealed microphallus, hypospadia and complete fusion of labioscrotal folds with nonpalpable gonads, normal blood pressure and serum biochemistry. Cortisol level was normal (201 nmol/L), testosterone elevated (14.4 nmol/L), FSH 0.1 IU/L, LH 0.7 IU/L, estradiol 241 pmol/L. Seizures were noted on the 2nd day and the child was started on anticonvulsives. When 17-OHP level results came back elevated (200 nmol/L), ACTH test was performed and the child was started on hydrocortisone and fludrocortisone treatment. Congenital adrenal hyperplasia became unlikely when karyotype result showed normal male karyotype (46, XY, SRY+) with no Mullerian structures seen on ultrasonographic exam. As association of ambiguous genitalia and lissencephaly strongly suggested a mutual genetic background, diagnosis of X-linked lissencephaly with ambiguous genitalia (X-LAG) became apparent. Conclusions. The presented case highlights the importance of looking at the whole clinical picture instead of separate isolated findings with emphasis on patient-centered approach guided by clinical findings and patient history. © 2021, Acta Endocrinologica Foundation. All rights reserved.

Glycogen storage disease (GSD) type I is inborn metabolic disease characterized by accumulation of glycogen in multiple organs. We analyzed 38 patients with clinical suspicion of GSD I using Sanger and next-generation sequencing (NGS). We identified 28 GSD Ib and 5 GSD Ia patients. In 5 patients, GSD III, VI, IX, cholesteryl-ester storage disease and Shwachman-Diamond syndrome diagnoses were set using NGS. Incidences for GSD Ia and GSD Ib were estimated at 1:172 746 and 1:60 461 live-births, respectively. Two variants were identified in G6PC gene: c.247C>T (p.Arg83Cys) and c.518T>C (p.Leu173Pro). In SLC37A4 gene, 6 variants were detected. Three previously reported variants c.81T>A (p.Asn27Lys), c.162C>A (p.Ser54Arg) and c.1042_1043delCT (p.Leu348Valfs*53) accounted for 87% of all analyzed alleles. Computational, transcription studies and/or clinical presentation in patients confirmed pathogenic effect of 3 novel variants: c.248G>A (p.Gly83Glu), c.404G>A (p.Gly135Asp) and c.785G>A (p.Ser263Glyfs*33 or p.Gly262Asp). In the cohort, hepatomegaly, hypoglycemia and failure to thrive were the most frequent presenting signs of GSD Ia, while hepatomegaly and recurrent bacterial infections were clinical hallmarks of GSD Ib. All GSD Ib patients developed neutropenia while 20.6% developed inflammatory bowel disease. Our study revealed the highest worldwide incidence of GSD Ib. Furthermore, description of 3 novel variants will facilitate medical genetic practice. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd

Glycogen storage disease (GSD) type I is inborn metabolic disease characterized by accumulation of glycogen in multiple organs. We analyzed 38 patients with clinical suspicion of GSD I using Sanger and next-generation sequencing (NGS). We identified 28 GSD Ib and 5 GSD Ia patients. In 5 patients, GSD III, VI, IX, cholesteryl-ester storage disease and Shwachman-Diamond syndrome diagnoses were set using NGS. Incidences for GSD Ia and GSD Ib were estimated at 1:172 746 and 1:60 461 live-births, respectively. Two variants were identified in G6PC gene: c.247C>T (p.Arg83Cys) and c.518T>C (p.Leu173Pro). In SLC37A4 gene, 6 variants were detected. Three previously reported variants c.81T>A (p.Asn27Lys), c.162C>A (p.Ser54Arg) and c.1042_1043delCT (p.Leu348Valfs*53) accounted for 87% of all analyzed alleles. Computational, transcription studies and/or clinical presentation in patients confirmed pathogenic effect of 3 novel variants: c.248G>A (p.Gly83Glu), c.404G>A (p.Gly135Asp) and c.785G>A (p.Ser263Glyfs*33 or p.Gly262Asp). In the cohort, hepatomegaly, hypoglycemia and failure to thrive were the most frequent presenting signs of GSD Ia, while hepatomegaly and recurrent bacterial infections were clinical hallmarks of GSD Ib. All GSD Ib patients developed neutropenia while 20.6% developed inflammatory bowel disease. Our study revealed the highest worldwide incidence of GSD Ib. Furthermore, description of 3 novel variants will facilitate medical genetic practice. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd

Mucopolysaccharidosis type II (Hunter syndrome, MPS II, OMIM 309900) is an X-linked lysosomal storage disorder caused by deficiency of iduronate-2-sulfatase (IDS). We analyzed clinical and laboratory data from 44 Slavic patients with this disease. In total, 21 Czech, 7 Slovak, 9 Croatian and 7 Serbian patients (43 M/1 F) were included in the study (median age 11.0 years, range 1.2–43 years). Birth prevalence ranged from 1:69,223 (Serbia) to 1:192,626 (Czech Rep.). In the majority of patients (71%), the disease manifested in infancy. Cognitive functions were normal in 10 patients. Four, six and 24 patients had mild, moderate, and severe developmental delay, respectively, typically subsequent to developmental regression (59%). Residual enzyme activity showed no predictive value, and estimation of glycosaminoglycans (GAGs) had only limited importance for prognosis. Mutation analysis performed in 36 families led to the identification of 12 novel mutations, eight of which were small deletions/insertions. Large deletions/rearrangements and all but one small deletion/insertion led to a severe phenotype. This genotype–phenotype correlation was also identified in six cases with recurrent missense mutations. Based on patient genotype, the severity of the disease may be predicted with high probability in approximately half of MPS II patients. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd

Mucopolysaccharidosis type II (Hunter syndrome, MPS II, OMIM 309900) is an X-linked lysosomal storage disorder caused by deficiency of iduronate-2-sulfatase (IDS). We analyzed clinical and laboratory data from 44 Slavic patients with this disease. In total, 21 Czech, 7 Slovak, 9 Croatian and 7 Serbian patients (43 M/1 F) were included in the study (median age 11.0 years, range 1.2–43 years). Birth prevalence ranged from 1:69,223 (Serbia) to 1:192,626 (Czech Rep.). In the majority of patients (71%), the disease manifested in infancy. Cognitive functions were normal in 10 patients. Four, six and 24 patients had mild, moderate, and severe developmental delay, respectively, typically subsequent to developmental regression (59%). Residual enzyme activity showed no predictive value, and estimation of glycosaminoglycans (GAGs) had only limited importance for prognosis. Mutation analysis performed in 36 families led to the identification of 12 novel mutations, eight of which were small deletions/insertions. Large deletions/rearrangements and all but one small deletion/insertion led to a severe phenotype. This genotype–phenotype correlation was also identified in six cases with recurrent missense mutations. Based on patient genotype, the severity of the disease may be predicted with high probability in approximately half of MPS II patients. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd

Specific mitochondrial enzymatic deficiencies in the catabolism of branched-chain amino acids cause methylmalonic aciduria (MMA), propionic acidemia (PA) and maple syrup urine disease (MSUD). Disease-causing mutations were identified in nine unrelated branched-chain organic acidurias (BCOA) patients. We detected eight previously described mutations: p.Asn219Tyr, p.Arg369His p.Val553Glyfs*17 in MUT, p.Thr198Serfs*6 in MMAA, p.Ile144_Leu181del in PCCB, p.Gly288Valfs*11, p.Tyr438Asn in BCKDHA and p.Ala137Val in BCKDHB gene. Interestingly, we identified seven novel genetic variants: p.Leu549Pro, p.Glu564*, p.Leu641Pro in MUT, p.Tyr206Cys in PCCB, p.His194Arg, p.Val298Met in BCKDHA and p.Glu286_Met290del in BCKDHB gene. In silico and/or eukaryotic expression studies confirmed pathogenic effect of all novel genetic variants. Aberrant enzymes p.Leu549Pro MUT, p.Leu641Pro MUT and p.Tyr206Cys PCCB did not show residual activity in activity assays. In addition, activity of MUT enzymes was not rescued in the presence of vitamin B12 precursor in vitro which was in accordance with non-responsiveness or partial responsiveness of patients to vitamin B12 therapy. Our study brings the first molecular genetic data and detailed phenotypic characteristics for MMA, PA and MSUD patients for Serbia and the whole South-Eastern European region. Therefore, our study contributes to the better understanding of molecular landscape of BCOA in Europe and to general knowledge on genotype–phenotype correlation for these rare diseases. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd

Specific mitochondrial enzymatic deficiencies in the catabolism of branched-chain amino acids cause methylmalonic aciduria (MMA), propionic acidemia (PA) and maple syrup urine disease (MSUD). Disease-causing mutations were identified in nine unrelated branched-chain organic acidurias (BCOA) patients. We detected eight previously described mutations: p.Asn219Tyr, p.Arg369His p.Val553Glyfs*17 in MUT, p.Thr198Serfs*6 in MMAA, p.Ile144_Leu181del in PCCB, p.Gly288Valfs*11, p.Tyr438Asn in BCKDHA and p.Ala137Val in BCKDHB gene. Interestingly, we identified seven novel genetic variants: p.Leu549Pro, p.Glu564*, p.Leu641Pro in MUT, p.Tyr206Cys in PCCB, p.His194Arg, p.Val298Met in BCKDHA and p.Glu286_Met290del in BCKDHB gene. In silico and/or eukaryotic expression studies confirmed pathogenic effect of all novel genetic variants. Aberrant enzymes p.Leu549Pro MUT, p.Leu641Pro MUT and p.Tyr206Cys PCCB did not show residual activity in activity assays. In addition, activity of MUT enzymes was not rescued in the presence of vitamin B12 precursor in vitro which was in accordance with non-responsiveness or partial responsiveness of patients to vitamin B12 therapy. Our study brings the first molecular genetic data and detailed phenotypic characteristics for MMA, PA and MSUD patients for Serbia and the whole South-Eastern European region. Therefore, our study contributes to the better understanding of molecular landscape of BCOA in Europe and to general knowledge on genotype–phenotype correlation for these rare diseases. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd

Cowden syndrome (CS) represents a rare autosomal dominant disorder caused by mutations in the PTEN gene located on chromosome 10q23.3. This entity belongs to the PTEN hamartoma tumor syndrome (PHTS) spectrum. The PTEN gene encodes a tumor suppressor protein crucial for regulating cell growth, survival, and apoptosis. Pathogenic mutations in PTEN result in dysregulated cell proliferation, manifesting clinically as benign and malignant growths across various tissues. CS is characterized by a predisposition to multiple hamartomas and an elevated risk of cancers, most notably in the skin, soft tissues, thyroid, breast, and gastrointestinal tract. In pediatric patients, macrocephaly is frequently the earliest feature, often accompanied by developmental delays and neurological deficits. This case series details the clinical evolution and multidisciplinary management of two siblings with CS and normal psychomotor development. Genetic testing identified a familial PTEN mutation, with multiple affected relatives, including the siblings’ father, paternal aunt and paternal grandfather, each displaying distinct phenotype. This familial clustering highlights the autosomal dominant inheritance of CS and points out the critical importance of early genetic testing, vigilant surveillance, and tailored counselling for at-risk relatives. Phenotypic variability observed between members of the same family points out the difficulties in predicting transgenerational outcomes and complicates genetic counselling. © 2024 Ilic N et al., published by Sciendo.

Cowden syndrome (CS) represents a rare autosomal dominant disorder caused by mutations in the PTEN gene located on chromosome 10q23.3. This entity belongs to the PTEN hamartoma tumor syndrome (PHTS) spectrum. The PTEN gene encodes a tumor suppressor protein crucial for regulating cell growth, survival, and apoptosis. Pathogenic mutations in PTEN result in dysregulated cell proliferation, manifesting clinically as benign and malignant growths across various tissues. CS is characterized by a predisposition to multiple hamartomas and an elevated risk of cancers, most notably in the skin, soft tissues, thyroid, breast, and gastrointestinal tract. In pediatric patients, macrocephaly is frequently the earliest feature, often accompanied by developmental delays and neurological deficits. This case series details the clinical evolution and multidisciplinary management of two siblings with CS and normal psychomotor development. Genetic testing identified a familial PTEN mutation, with multiple affected relatives, including the siblings’ father, paternal aunt and paternal grandfather, each displaying distinct phenotype. This familial clustering highlights the autosomal dominant inheritance of CS and points out the critical importance of early genetic testing, vigilant surveillance, and tailored counselling for at-risk relatives. Phenotypic variability observed between members of the same family points out the difficulties in predicting transgenerational outcomes and complicates genetic counselling. © 2024 Ilic N et al., published by Sciendo.

Succinic semialdehyde dehydrogenase (SSADH) deficiency is a rare autosomal-recessive disorder of gamma-aminobutyric acid (GABA) metabolism, resulting in accumulation of GABA and gamma-hydroxybutyric acid (GHB) in physiological fluids. Approximately 450 patients have been diagnosed worldwide with this inherited neurotransmitter disorder. We report on a five-year-old male patient, homozygous for the pathogenic variant (NM_170740:c.1265G>A) in ALDH5A1 presenting with an unexpected association of typical SSADH deficiency manifestations with bilateral sensorineural hearing loss (SNHL). Brainstem evoked response audiometry (BERA) testing showed mid-frequency sensorineural hearing damage that suggested a hereditary component to SNHL. Whole exome sequencing (WES) failed to discern other genetic causes of deafness. Several variants of uncertain significance (VUS) detected in genes known for their role in hearing physiology could not be verified as the cause for the SNHL. It is known that central auditory processing depends on a delicate balance between excitatory and inhibitory neurotransmission, and GABA is known to play a significant role in this process. Additionally, excessive concentrations of accumulated GABA and GBH are known to cause a down-regulation of GABA receptors, which could have an adverse influence on hearing function. However, these mechanisms are very speculative in context of SNHL in a patient with inherited disorder of GABA metabolism. Injury of the globi pallidi, one of hallmarks of SSADH deficiency, could also be a contributory factor to SNHL, as was suspected in some other inborn errors in metabolism. We hope that this case will contribute to the understanding of phenotypic complexity of SSADH deficiency. © 2023 M Parezanović et al., published by Sciendo.

Succinic semialdehyde dehydrogenase (SSADH) deficiency is a rare autosomal-recessive disorder of gamma-aminobutyric acid (GABA) metabolism, resulting in accumulation of GABA and gamma-hydroxybutyric acid (GHB) in physiological fluids. Approximately 450 patients have been diagnosed worldwide with this inherited neurotransmitter disorder. We report on a five-year-old male patient, homozygous for the pathogenic variant (NM_170740:c.1265G>A) in ALDH5A1 presenting with an unexpected association of typical SSADH deficiency manifestations with bilateral sensorineural hearing loss (SNHL). Brainstem evoked response audiometry (BERA) testing showed mid-frequency sensorineural hearing damage that suggested a hereditary component to SNHL. Whole exome sequencing (WES) failed to discern other genetic causes of deafness. Several variants of uncertain significance (VUS) detected in genes known for their role in hearing physiology could not be verified as the cause for the SNHL. It is known that central auditory processing depends on a delicate balance between excitatory and inhibitory neurotransmission, and GABA is known to play a significant role in this process. Additionally, excessive concentrations of accumulated GABA and GBH are known to cause a down-regulation of GABA receptors, which could have an adverse influence on hearing function. However, these mechanisms are very speculative in context of SNHL in a patient with inherited disorder of GABA metabolism. Injury of the globi pallidi, one of hallmarks of SSADH deficiency, could also be a contributory factor to SNHL, as was suspected in some other inborn errors in metabolism. We hope that this case will contribute to the understanding of phenotypic complexity of SSADH deficiency. © 2023 M Parezanović et al., published by Sciendo.