Beta thalassemia is a serious disease for which mutation-based diagnostic and screening tests are readily available. These tests are based on specific variant profile in the regions of the testing centers. De novo mutations and migration change the distribution of these variants. We aim to update the variant spectrum in the gene in our region. In addition, we present a variant, which not been detected before in Turkey, and also a changed classification of another variant.

Christianson syndrome is a rare neurodevelopmental disorder associated with mutations in the gene located on the chromosome X. It is characterized by intellectual disability, developmental delay, speech and language impairments, dysmorphic features, seizures, ataxia, and neurobehavioral problems.

Xia-Gibbs syndrome (XGS) is a rare syndromic disorder characterized by developmental delay with intellectual disability, muscular hypotonia, brain anomalies, and nonspecific dysmorphic features. Different heterozygous variants in have been reported as causal for XGS, comprising mainly stop-gain and frameshift events, but also missense variants, deletions, and a duplication of the locus.

Spondyloepiphyseal dysplasia (SED) is characterized by skeletal dysplasia and multiple joint dislocations. SEDs encompass various types, such as SED congenita, SED tarda (SED-T), SED with congenital joint dislocations (SED-CJD), SED stanescu, and SED-T with progressive arthropathy.

Congenital anomalies of the kidney and urinary tract (CAKUT) are characterized by several malformations. Its prevalence is 0.3-0.6% in live births. The B-cell lymphoma () gene regulates apoptosis, and the Leukemia Inhibitory Factor () gene plays a role in many biological processes, such as blastocyst growth and uterine preparation for implantation. In this study, two single nucleotide polymorphisms (SNPs) of the gene (rs2279115 and rs4987856) and one SNP of the gene (rs929271) were investigated in CAKUT patients for the first time.

encodes eukaryotic elongation factor 2 which catalyzes the elongation phase of protein translation. It is ubiquitously expressed and important for neuronal function. was first associated with adult-onset spinocerebellar ataxia type 26 (SCA26). A novel neurodevelopmental disorder associated with de novo heterozygous variants in has been described. Only 6 patients have been described in the literature thus far. A 9-year-old child with de novo novel missense variant is described here. -related neurodevelopmental disorder appears to be clinically recognizable.

Congenital diarrhea presents a diagnostic challenge in cases where standard assessments are inconclusive.

Peroxisome biogenesis disorders (PBDs) encompass a group of diseases marked by clinical and genetic heterogeneity. Phenotypes linked to PBDs include Zellweger syndrome, neonatal adrenoleukodystrophy, infantile Refsum disease (IRD), rhizomelic chondrodysplasia punctata type 1, and Heimler syndrome. PBD phenotypes manifest through hypotonia, developmental delay, facial dysmorphism, seizures, liver dysfunction, sensorineural hearing loss, and retinal dystrophy.

Linkeropathies are a group of rare multi-systemic genetic disorders primarily affecting the skeletal and cardiac systems due to defects in the enzymes responsible for proteoglycan synthesis.

As with many genetic diseases, the diagnostic role of next-generation sequencing is invaluable for early-onset epileptic encephalopathies. SNARE proteins in synaptic vesicles (synaptobrevin-2) and synaptic plasma membrane (syntaxin-1, SNAP-25) are involved in synaptic exocytosis and recycling.

Glutamate-cysteine ligase catalytic subunit (GCLC), previously known as gamma-glutamyl-cysteine synthetase, is an essential rate-limiting step in glutathione synthesis. Glutathione modulates multitudes of critical cellular processes and scavenges free radicals. Its deficiency is reported to cause hemolysis of variable severity and is a rare cause of neurological abnormalities such as spinocerebellar ataxia.

Pathogenic variants in the gene are associated to a large spectrum of severe early onset developmental and epileptic encephalopathies (OMIM #612164). They were also identified in various other neurodevelopmental disorders. This gene encodes for the syntaxin-binding protein 1, a member of the SEC-1 family of membrane-transport proteins that modulate the presynaptic vesicular fusion by interacting with soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs). However, the physiopathology of pathogenic variants is not yet fully understood.

Kallmann syndrome (KS) is a genetically heterogeneous developmental disorder that most often manifests hypogonadotropic hypogonadism (HH) and hypo-/anosmia due to early embryonic impairment in the migration of gonadotropin-releasing hormone neurons. (SRY-Box 10; MIM*602229), a key transcriptional activator involved in the development of neural crest cells, has been associated with KS and is identified as one of the causative genes of Waardenburg syndrome (WS).

Smith-Lemli-Opitz syndrome (SLOS), a genetic developmental disorder characterized by various congenital anomalies, arises from a loss of normal enzymatic action in cholesterol biosynthesis. This syndrome is typically marked by various congenital anomalies, including microcephaly with cognitive impairments, distinctive facial features, and syndactyly of the toes (2-3 fusion).

Leigh syndrome is a rare mitochondrial disorder characterized by subacute necrotizing encephalomyelopathy, resulting from defects in mitochondrial respiratory enzymes or pyruvate dehydrogenase complex. Symptoms can manifest in infancy, childhood, or adulthood. We present a case of a 7-month-old girl initially misdiagnosed with septic shock but was later found to have Leigh encephalomyelopathy due to deficiency.

Lateral meningocele syndrome (LMS), also known as Lehman syndrome, is caused by pathogenic variants in exon 33 of . Variants in this final exon of interrupt the regulatory PEST domain, leading to enhanced signaling due to prolonged cellular half-life. Individuals with LMS are expected to have multiple lateral meningoceles, developmental delay, neonatal hypotonia, dysmorphic facial features, and feeding difficulties.

UV-sensitive syndrome and Cockayne syndrome (CS) are rare autosomal recessive and transcription-coupled nucleotide excision repair disorders with different clinical manifestations, although some types are allelic.

Diencephalic-mesencephalic junction dysplasia syndrome is a rare neurogenetic disorder reported to be caused by variants in several genes. Phenotypic presentation is characterized by clinical findings including developmental delay, hypotonia, spasticity, and dyskinetic movements in combination with distinctive imaging features on brain magnetic resonance imaging (MRI).

Mutations in collagen type IV-associated genes lead to Ullrich congenital muscular dystrophy (UCMD) and Bethlem myopathy (BM). gene mutations have rarely been reported in patients with UCMD- and BM-like disorders not involving mutations. UCMD-2 results from homozygous mutations in the gene on the long arm of chromosome 6. Pathogenic variants in result in a rare congenital connective tissue/myopathy overlap syndrome under the heading of myopathic Ehlers-Danlos syndrome. dominant pathogenic variants have been rarely reported, and the phenotypic spectrum has not yet been identified.

Inherited 5-oxoprolinase (OPLAH) deficiency is a rare inborn condition characterized by 5-oxoprolinuria. The inherited condition of 5-oxoprolinuria, or pyroglutamic aciduria, is primarily caused by mutations in the genes that encode glutathione synthetase (GSS) and 5-oxoprolinase (OPLAH), which are enzymes involved in the gamma-glutamyl cycle in glutathione metabolism. We report a 3-year-old male patient with epilepsy and speech difficulty diagnosed as primary 5-oxoprolinuria due to a novel gene mutation.

Primrose syndrome (PS; MIM #259050) is a rare autosomal dominant genetic condition characterized by macrocephaly with or without tall stature, hypotonia, moderate to severe intellectual disability (ID) with delay in expressive speech development, behavioral abnormalities, and a recognizable facial phenotype including deep set eyes, ptosis, narrow and frequently downslanting palpebral fissures, and depressed nasal bridge. PS is caused by a heterozygous pathogenic variant in (MIM #606025) on chromosome 3q13. Among other characteristic findings are ocular abnormalities, hearing loss, calcification of the external ear cartilage, nonspecific brain magnetic resonance imaging findings, and cryptorchidism. Adults may exhibit joint contractures, distal muscle wasting, sparse body hair, cataract, and disturbed glucose metabolism as well. The majority of affected individuals have typically been adults until recently since the phenotype becomes more recognizable in time.