Case Reports in Genetics最新文献

Background: Mitochondrial DNA depletion syndrome 13 (MTDPS13) is an autosomal recessive disorder presenting in early infancy with encephalopathy, hypotonia, lactic acidosis, and severe global developmental delay. Patient-derived cells typically exhibit impaired mitochondrial oxidative phosphorylation and a marked reduction in mitochondrial DNA (mtDNA) copy number.

Case report: We report the case of a male preterm neonate born at 31 + 3 weeks of gestation following a pregnancy marked by severe polyhydramnios. At birth, his weight was 1400 g. Physical examination revealed dysmorphic features, redundant and lax skin, and generalized muscular hypotonia. Laboratory investigations showed marked lactic acidosis associated with lactic aciduria, ketonuria, and urinary biomarkers indicating activation of preoxidative phosphorylation biochemical pathways to sustain ATP production. Echocardiography demonstrated mild, early-onset hypertrophic cardiomyopathy. The Exome Analysis Clinical and Biochemical Markers: The exome analysis, performed within the first week of life, highlighted a pathogenic variant in homozygous state of FBXL4 gene (c.1648_1649delGA), which led to the diagnosis of MTDPS13. In this clinical contest, a ketogenic diet (KD) was started with a daily caloric intake of 120 kcal/kg and an initial ketogenic ratio of 1:1. These intakes were administered both with a parenteral nutrition and continuous nasogastric tube feeding and were gradually increased and adapted on a day-by-day basis according to lactic acidosis, growth increase, and common metabolic parameters such as glucose, electrolytes, creatinine, and blood urea nitrogen. After 3 days of this treatment approach, a significant reduction in lactate levels and improvement in acid-base balance and growth trend were observed along with clinical and cardiovascular parameters. At discharge from neonatal intensive care unit, the KD was continued at home and during follow-up. The infant showed stability in the clinical and biochemical markers.

Conclusions: This is the first documented report of the use of a KD in a preterm neonate with this mitochondrial disorder during the early days of life. Prompt genetic confirmation and early initiation of KD may enable a more targeted and effective management of MTDPS within the neonatal intensive care setting.

Trisomy 8 mosaicism (T8M) syndrome is a rare aneuploidy condition affecting 1/25,000-50,000 live births. Affected individuals have highly variable phenotypes from very mild dysmorphism to severe structural anomalies caused by chromosomal mosaicism and possibly undetected molecular aberrations. The utilization of chromosome microarray analysis (CMA) and exome sequencing (ES) in clinical laboratories enable the identification of genomic copy number imbalances and pathogenic gene variants. We presented one patient with a double aneuploid mosaic pattern of Monosomy X and Trisomy 8 for a compound phenotype of Turner syndrome (TS) and T8M syndrome, the second patient with T8M and a mosaic pathogenic variant in the PTEN gene detected by ES, and the third patient with typical phenotypic constellation of malformations with no other genetic aberrations detected by CMA and ES. Classification of mosaic findings was provided using a recommended six-attribute scheme. Review of the literature summarized cases of T8M with concomitant molecular defects of a deletion at 22q11.2 and pathogenic variants in the SALL1, RECQL4, NF1, CASK, and PAH genes. These observations indicated that integrated cytogenetic and genomic analyses should be offered to patients with phenotypic abnormalities outside the spectrum of the T8M syndrome for comprehensive laboratory diagnosis and clinical management.

Background: Hypokalemic periodic paralysis (HypoPP) is a rare skeletal muscle channelopathy, most often caused by mutations in CACNA1S or SCN4A. Most pathogenic CACNA1S mutations affect arginine residues in S4 voltage-sensor domains, but other variants remain poorly understood.

Case presentation: I describe a 30-year-old Caucasian woman with recurrent paralytic episodes and hypokalemia (2.1-2.3 mmol/L), triggered by stress and carbohydrate-rich meals. Genetic testing revealed heterozygosity for CACNA1S c.3727C  >  G (p.Leu1243Val), a variant of uncertain significance not previously associated with pathogenicity. Her phenotype was consistent with HypoPP. Treatment with spironolactone and acetazolamide reduced episode frequency, although the latter caused intolerable side effects, particularly tachypnea; she was later approved for dichlorphenamide. During one hospitalization, she also developed transient hypophosphatemia and hypokalemia, consistent with her HypoPP picture. Kidney function and imaging were normal. Family history revealed electrolyte disturbances in her grandfather.

Conclusions: This case highlights a possible genotype-phenotype link involving CACNA1S p.Leu1243Val. Continued reporting of such cases is essential for variant reclassification and for improving recognition of metabolic shifts during HypoPP attacks.

Gastric adenocarcinoma and proximal polyposis of the stomach (GAPPS) is a rare autosomal dominantly inherited gastric cancer syndrome that is characterized by fundic gland polyposis of the stomach (> 100) and an increased risk of gastric cancer. The genetic cause is recognized as a pathogenic variant in the promotor 1B of the APC gene. Presently, there are no established clinical criteria, and current guidelines are based on limited evidence. In this report, we identified two families with GAPPS. Family I had a family history of gastric cancer, and we identified seven family members with GAPPS. The diagnosis was verified by endoscopic findings of polyposis and genetic analysis identifying a variant in the promotor 1B of the APC gene, NM_001127511.3: c.-191T > C. In Family II, the same pathogenic variant, NM_001127511.3: c.-191T > C, was detected as an incidental finding in a 61-year-old patient with hepatocellular carcinoma, clear cell renal carcinoma, and small cell lung cancer. An esophagogastroduodenoscopy (EGD) at the age of 59 had revealed only one small fundic polyp. This is the first report of patients with GAPPS from Denmark, and it emphasizes the variable phenotypic expression and subsequently the difficulty of surveillance and genetic counseling in these patients and their families.

Primary ciliary dyskinesia (PCD) is a rare and heterogeneous inherited disease characterized by impaired mucociliary clearance. Patients with PCD typically present with recurrent respiratory infections resulting in the development of bronchiectasis. Even though awareness of the disease has increased over the years, PCD remains underdiagnosed. We here present a case of a newly diagnosed middle-aged female found to have a previously undescribed variant of the disease-associated DNAAF3 gene.

[This corrects the article DOI: 10.1155/2024/6009569.].

Primary familial basal ganglia calcification (PFBC), also known as Fahr's disease, is a rare neurodegenerative condition characterized by bilateral calcifications in the basal ganglia and other brain regions. While it predominantly presents in adulthood and is commonly associated with heterozygous mutations, rare homozygous pathogenic variants may lead to severe early-onset manifestations. We present a unique case of PFBC in a 2-month-old female infant who exhibited focal motor seizures shortly after routine immunization. Neuroimaging revealed bilateral basal ganglia calcifications, multifocal cerebral infarcts, and evidence of significant intra-arterial cerebral vasculopathy. Genetic testing confirmed a homozygous pathogenic variant in the SLC20A2 gene (c.1399 C > T) (p.R467∗). Notably, both consanguineous parents were heterozygous carriers of the same mutation. Other family members across two generations also harbored heterozygous variants but were asymptomatic. This case is one of the few reported instances of a homozygous SLC20A2 pathogenic variant and the second to demonstrate intra-arterial vasculopathy in infancy. The clinical spectrum included seizures, hypotonia, poor feeding, and extensive ischemic changes. Despite supportive care and antiepileptic therapy, the patient remained neurologically impaired. This report underscores the importance of considering PFBC in the differential diagnosis of infantile seizures, especially in populations with high rates of consanguinity. It also expands the phenotypic spectrum of SLC20A2-related disease to include infantile stroke due to cerebral vasculopathy. Early diagnosis and genetic counseling are essential for management and family planning.

Baker-Gordon syndrome (BAGOS) is an autosomal dominant neurodevelopmental disorder caused by de novo heterozygous missense mutations in SYT1. The precise pathogenic mechanism of BAGOS is still unclear, with preliminary data favoring a dominant-negative effect, although a previous case presenting a reciprocal translocation disrupting SYT1 supports haploinsufficiency as a possible mechanism. We report a child with a syndromic neurodevelopmental disorder compatible with BAGOS and carrying a t(5; 12)(q31; q21) by G-banded karyotype. Optical genome mapping (OGM) is based on ultrahigh molecular weight DNA molecules allowing the combined analyses of numerical and structural chromosome variants. The rearrangement was investigated using OGM, which revealed an additional structural variant, a paracentric inversion in the segment of Chromosome 12 translocated to der(5). The breakpoint of the paracentric inversion is mapped to Intron 9 of the SYT1 gene, interrupting the C2B domain. This is the second BAGOS case reported in the literature caused by SYT1 disruption, supporting that reduced amounts of functional SYT1, either by haploinsufficiency or dominant-negative effect, is responsible for SYT1-associated neurodevelopmental syndrome.

Background: Monocarboxylate transporter 8 (MCT8) deficiency, also known as Allan-Herndon-Dudley syndrome, is a rare X-linked genetic disorder resulting from pathogenic mutations in the SLC16A2 gene. MCT8 deficiency impacts the transport of thyroid hormone (TH) throughout the body. Symptoms are highly heterogeneous and often include severe neurodevelopmental delay, hypotonia in the limbs and trunk, and low body weight.

Case presentation: This case report describes the diagnostic journey of two brothers born 1 year and 8 months apart to nonconsanguineous parents. Both exhibited severely limited motor development, quadriparesis, and an inability to sit independently or hold their head up. Despite their significant clinical presentations, the diagnoses were delayed: 12 years and 8 months for Case 1 and 8 years and 3 months for Case 2. Genetic testing revealed that both patients carry the same novel SLC16A2 mutation, 960_995del (p.Tyr321_Ala332del). Although they displayed key clinical features of MCT8 deficiency, the TH profile of Case 1 was inconclusive, lacking the characteristic sustained elevation of triiodothyronine (T3) typically associated with MCT8 deficiency.

Conclusions: Findings from this case report highlight the need for greater awareness of this disorder and underscore the clinical heterogeneity of MCT8 deficiency.

Diaphragmatic rupture is an uncommonly seen complication of classical Ehlers-Danlos syndrome (cEDS). There have been no documented cases of diaphragmatic hernia in newborns having cEDS. This case study discusses a male infant delivered through spontaneous vertex delivery to a mother with cEDS. No evidence of a diaphragmatic hernia was found 6 days before delivery when an ultrasound scan to monitor a ventricular septal defect was carried out. Postnatally, the infant displayed signs of severe respiratory distress. A chest radiograph revealed a diaphragmatic hernia. The surgical team found and corrected a small posterolateral diaphragmatic defect on the third day of life. This resulted in a good recovery following management of a complication of chylothorax. The mother was known to have cEDS and bidirectional sequencing of the patient's lymphocyte DNA detected the heterozygous pathogenic familial variant COL1A1 c.934C > T;p.(Arg312Cys). This variant has been previously reported in cases of cEDS. Other COL1A1 variants are known to be associated with arthrochalasia-type EDS and osteogenesis imperfecta, but no COL1A1 variants have been associated previously with congenital diaphragmatic hernia or diaphragmatic rupture. The familial variant impacts the highly conserved arginine residue in the Gly-X-Y triplet motif of the Type-I collagen protein. It has been reported in various families as a rare cause of autosomal-dominant cEDS. This case report details the patient's journey, including images of radiographs, highlighting a rare but important complication of spontaneous vertex delivery for individuals with cEDS. We also include a literature review on diaphragmatic hernia and rupture in classical EDS.