A case of brain-lung-thyroid syndrome. / 脑-肺-ç”²çŠ¶è ºç»¼åˆå¾1例.

Brain-lung-thyroid syndrome is a rare autosomal dominant disorder. More than 100 cases have been reported worldwide, but few cases have been reported in China. In December 2018, a boy with brain-lung-thyroid syndrome, aged 3 years and 10 months, was admitted to Xiangya Hospital of Central South University due to repeated cough for more than 3 years. In infancy of the boy, psychomotor retardation, repeated cough, and hypothyroidism were found. Gene detection showed that there was c.927delc heterozygous variation in NKX2-1 gene (NM-001079668: exon3: c.927delC). The variation of this gene locus has not been reported in relevant literature so far, which indicates a new mutation. According to the above clinical manifestations and examination results, the boy was diagnosed as brain-lung-thyroid syndrome, which mainly characterized by nervous system disorders, accompanied by respiratory manifestations and hypothyroidism. The boy was treated with oral dopasehydrazine to relieve tremor and levothyroxine sodium tablets to relieve hypothyroidism. Anti-infection, atomization, rehabilitation training and other symptomatic supporting treatment were also administered. The boy's language and movement have improved, the thyroid hormone level is normal, and there are still repeated respiratory tract infections.

A case of brain-lung-thyroid syndrome / 中南大学学报(医学版)

Brain-lung-thyroid syndrome is a rare autosomal dominant disorder. More than 100 cases have been reported worldwide, but few cases have been reported in China. In December 2018, a boy with brain-lung-thyroid syndrome, aged 3 years and 10 months, was admitted to Xiangya Hospital of Central South University due to repeated cough for more than 3 years. In infancy of the boy, psychomotor retardation, repeated cough, and hypothyroidism were found. Gene detection showed that there was c.927delc heterozygous variation in NKX2-1 gene (NM-001079668: exon3: c.927delC). The variation of this gene locus has not been reported in relevant literature so far, which indicates a new mutation. According to the above clinical manifestations and examination results, the boy was diagnosed as brain-lung-thyroid syndrome, which mainly characterized by nervous system disorders, accompanied by respiratory manifestations and hypothyroidism. The boy was treated with oral dopasehydrazine to relieve tremor and levothyroxine sodium tablets to relieve hypothyroidism. Anti-infection, atomization, rehabilitation training and other symptomatic supporting treatment were also administered. The boy's language and movement have improved, the thyroid hormone level is normal, and there are still repeated respiratory tract infections.

Characterization of the GABRB2-Associated Neurodevelopmental Disorders.

OBJECTIVE: We aimed to characterize the phenotypic spectrum and functional consequences associated with variants in the gene GABRB2, coding for the γ-aminobutyric acid type A (GABAA ) receptor subunit ß2. METHODS: We recruited and systematically evaluated 25 individuals with variants in GABRB2, 17 of whom are newly described and 8 previously reported with additional clinical data. Functional analysis was performed using a Xenopus laevis oocyte model system. RESULTS: Our cohort of 25 individuals from 22 families with variants in GABRB2 demonstrated a range of epilepsy phenotypes from genetic generalized epilepsy to developmental and epileptic encephalopathy. Fifty-eight percent of individuals had pharmacoresistant epilepsy; response to medications targeting the GABAergic pathway was inconsistent. Developmental disability (present in 84%) ranged from mild intellectual disability to severe global disability; movement disorders (present in 44%) included choreoathetosis, dystonia, and ataxia. Disease-associated variants cluster in the extracellular N-terminus and transmembrane domains 1-3, with more severe phenotypes seen in association with variants in transmembrane domains 1 and 2 and the allosteric binding site between transmembrane domains 2 and 3. Functional analysis of 4 variants in transmembrane domains 1 or 2 (p.Ile246Thr, p.Pro252Leu, p.Ile288Ser, p.Val282Ala) revealed strongly reduced amplitudes of GABA-evoked anionic currents. INTERPRETATION: GABRB2-related epilepsy ranges broadly in severity from genetic generalized epilepsy to developmental and epileptic encephalopathies. Developmental disability and movement disorder are key features. The phenotypic spectrum is comparable to other GABAA receptor-encoding genes. Phenotypic severity varies by protein domain. Experimental evidence supports loss of GABAergic inhibition as the mechanism underlying GABRB2-associated neurodevelopmental disorders. ANN NEUROL 2021;89:573-586.

Hypoxaemia and interstitial lung disease in an infant with hypothyroidism and hypotonia.

A 7-month-old-term male infant presented with cough, tachypnoea, hypoxaemia and post-tussive emesis. Clinical history was significant for respiratory failure and pulmonary hypertension in the neonatal period requiring assisted ventilation, congenital hypothyroidism, mild hypotonia, recurrent respiratory infections, hypoxaemia requiring supplemental oxygen and nasogastric tube feeds. Physical examination showed tachypnoea, coarse bilateral breath sounds and mild hypotonia. Chest radiograph revealed multifocal pulmonary opacities with coarse interstitial markings and right upper lobe atelectasis. Following antibiotic therapy for suspected aspiration pneumonia, chest CT scan was performed and showed multiple areas of pulmonary consolidation and scattered areas of bilateral ground-glass opacities. Genetic studies showed a large deletion of chromosome 14q13.1-14q21.1, encompassing the NK2 homeobox 1 (NKX2-1) gene consistent with a diagnosis of brain-thyroid-lung (BTL) syndrome. Our case highlights the importance of genetic studies to diagnose BTL syndrome in infants with hypothyroidism, hypotonia and lung disease.

Combined mutations of NKX2-1 and surfactant protein C genes for refractory low oxyhemoglobin saturation and interstitial pneumonia: A case report.

RATIONALE: Mutations of the NKX2-1 gene are associated with brain-lung-thyroid syndrome, which is characterized by benign hereditary chorea, hypothyroidism, and pulmonary disease with variable presentation. Surfactant protein C (SFTPC) gene mutations result in chronic interstitial lung disease in adults or severe neonatal respiratory distress syndrome. PATIENT CONCERNS: Recurrent hypoxemia was observed shortly after birth in a baby at a gestational age of 40 weeks and birth weight of 3150 g. The need for respiratory support gradually increased. He had hypothyroidism and experienced feeding difficulties and irritability. DIAGNOSIS: Genetic examination of the peripheral blood revealed combined mutations of the NKX2-1 and SFTPC genes. INTERVENTIONS: The patient was administered respiratory support, antibiotics, low-dose dexamethasone, supplementary thyroxine, venous nutrition, and other supportive measures. OUTCOMES: The patient's guardian stopped treatment 3 months after commencement of treatment, due to the seriousness of his condition and the patient died. LESSONS: Combined mutations of NKX2-1 and SFTPC genes are very rare. Thus, idiopathic interstitial pneumonia with hypothyroidism and neurological disorders require special attention.

Haploinsufficiency of NKX2-1 in Brain-Lung-Thyroid Syndrome with Additional Multiple Pituitary Dysfunction.

INTRODUCTION: Heterozygous mutations or haploinsufficiency of NKX2-1 are associated with the brain-lung-thyroid syndrome incorporating primary hypothyroidism, respiratory distress, and neurological disturbances. CASE PRESENTATION: We report a patient presenting in the neonatal period with multiple pituitary hormone deficiency including central hypothyroidism and hypoadrenalism, growth hormone deficiency, undetectable gonadotrophins, and a small anterior pituitary on MRI. CGH microarray revealed haploinsufficiency for NKX2.1 and during subsequent follow-up, she has exhibited the classic triad of brain-lung-thyroid syndrome with undetectable tissue on thyroid ultrasonography. Whilst the role of NKX2-1 is well described in murine pituitary development, this report constitutes the first description of multiple pituitary dysfunction in humans associated with the syndrome and haploinsufficiency NKX2-1. CONCLUSION: The report highlights a potential need for pituitary screening in patients with established brain-lung-thyroid syndrome and implicates NKX2.1 in human pituitary disease.

High-resolution computed tomography findings of thyroid transcription factor 1 deficiency (NKX2-1 mutations).

BACKGROUND: The expression of the NKX2-1 gene and its encoded protein, thyroid transcription factor 1 (TTF-1), plays a role in pulmonary surfactant homeostasis and lung development. NKX2-1 mutations have been associated with neonatal respiratory distress, hypotonia, choreoathetosis and congenital hypothyroidism. These clinical findings have been coined brain-lung-thyroid syndrome, although not all three organs are always involved. While many of these children develop interstitial lung disease, no systematic review of chest high-resolution CT (HRCT) findings has been reported. OBJECTIVE: To summarize the clinical presentations, pathology and HRCT imaging findings of children with NKX2-1 mutations. MATERIALS AND METHODS: We identified six children with NKX2-1 mutations, deletions or duplications confirmed via genetic testing at our institution. Three pediatric radiologists reviewed the children's HRCT imaging findings and ranked the dominant findings in order of prevalence via consensus. We then correlated the imaging findings with histopathology and clinical course. RESULTS: All children in the study were heterozygous for NKX2-1 mutations, deletions or duplications. Ground-glass opacities were the most common imaging feature, present in all but one child. Consolidation was also a prevalent finding in 4/6 of the children. Architectural distortion was less common. CONCLUSION: HRCT findings of TTF-1 deficiency are heterogeneous and evolve over time. There is significant overlap between the HRCT findings of TTF-1 deficiency, other surfactant dysfunction mutations, and pulmonary interstitial glycogenosis. TTF-1 deficiency should be considered in term infants presenting with interstitial lung disease, especially if hypotonia or hypothyroidism is present.

The Brain-Lung-Thyroid syndrome (BLTS): A novel deletion in chromosome 14q13.2-q21.1 expands the phenotype to humoral immunodeficiency.

Genetic defects of NKX2-1 are classically associated with hypothyroidism, benign chorea and neonatal respiratory distress. The purpose of this study was to identify the genetic pathogenesis of the "NKX2-1 triad" in a 10 year-old female presenting additional features barely described in the disorder. In the neonatal period, she presented with generalized hypotonia and respiratory distress, with later episodes of frequent wheezing. At 3 month-age developmental dysplasia of the hip was diagnosed and at 10 months, primary hypothyroidism was detected and treated. Subsequently, delayed achievement of developmental milestones and then subtle choreic movements of extremities were identified at 2 years of age. Furthermore, delayed teeth eruption and agenesis of some dental pieces, short stature and joint hyperlaxity were also noticed. At 10 years, a poor immune response to polysaccharide antigens and hypogammaglobulinemia, including all IgG subclasses were detected. Surprisingly, no mutations were identified in the complete coding region of NKX2-1 by PCR and Sanger sequencing. MLPA showed a de novo loss of gene dosage in all 3 probes located in NKX2-1 exons. A CGH-array identified a deletion of 3.32 Mb in chromosome 14q13.2-q21.1 containing 20 genes, including NKX2-1, PAX9 and two candidate genes (NFKB1A and PPP2R3C) involved in immune response. The Brain-Lung-Thyroid syndrome (OMIM#610978; ORPHA:209905) associated with other clinical phenotypes should suggest monoallelic deletions of chromosome 14 causing haploinsufficiency of NKX2-1, and other contiguous genes like PAX9 (hypodontia) or other dosage-sensitive genes in the chromosomal vicinity that emerge as candidates for hypogammaglobulinemia, mainly NFKBIA.

TAZ/WWTR1 Mediates the Pulmonary Effects of NKX2-1 Mutations in Brain-Lung-Thyroid Syndrome.

Context: Identification of a frameshift heterozygous mutation in the transcription factor NKX2-1 in a patient with brain-lung-thyroid syndrome (BLTS) and life-threatening lung emphysema. Objective: To study the genetic defect that causes this complex phenotype and dissect the molecular mechanism underlying this syndrome through functional analysis. Methods: Mutational study by DNA sequencing, generation of expression vectors, site-directed mutagenesis, protein-DNA-binding assays, luciferase reporter gene assays, confocal microscopy, coimmunoprecipitation, and bioinformatics analysis. Results: We identified a mutation [p.(Val75Glyfs*334)] in the amino-terminal domain of the NKX2-1 gene, which was functionally compared with a previously identified mutation [p.(Ala276Argfs*75)] in the carboxy-terminal domain in other patients with BLTS but without signs of respiratory distress. Both mutations showed similar protein expression profiles, subcellular localization, and deleterious effects on thyroid-, brain-, and lung-specific promoter activity. Coexpression of the coactivator TAZ/WWTR1 (transcriptional coactivator with PDZ-binding motif/WW domain-containing transcription regulator protein 1) restored the transactivation properties of p.(Ala276Argfs*75) but not p.(Val75Glyfs*334) NKX2-1 on a lung-specific promoter, although both NKX2-1 mutants could interact equally with TAZ/WWTR1. The retention of residual transcriptional activity in the carboxy-terminal mutant, which was absent in the amino-terminal mutant, allowed the functional rescue by TAZ/WWTR1. Conclusions: Our results support a mechanistic model involving TAZ/WWTR1 in the development of human congenital emphysema, suggesting that this protein could be a transcriptional modifier of the lung phenotype in BLTS.

Novel Mutations in the NKX2.1 gene and the PAX8 gene in a Boy with Brain-Lung-Thyroid Syndrome.

OBJECTIVE: To elucidate the molecular mechanism which causes thyroid dysgenesis (TD) in a boy with brain-lung-thyroid syndrome. DESIGN, PATIENTS, MEASUREMENTS: We describe a patient with TD, respiratory disease and cerebral palsy who is heterozygous for mutations in two different genes, the PAX8 (p.E234K) and the NKX2.1 (p.A329GfsX108). In vitro studies were performed to functionally characterize these mutations. Congenital hypothyroidism (CH) was identified by neonatal screening associated with a hypoplastic thyroid gland. Postpartum he developed a brain-lung-thyroid syndrome with severe respiratory failure, symptomatic epilepsy and a considerable psychomotor retardation. The DNA-binding capability and the transcriptional activity of the two mutated transcription factors were investigated in vitro. RESULTS: The NKX2.1 mutation did not show any transcriptional activity and had almost no DNA-binding. The PAX8 mutation was normally located to the nucleus and showed a normal transactivation and a normal binding to the known downstream targets. CONCLUSIONS: The molecular defect explaining the phenotype of brain-lung-thyroid syndrome was identified. To what extent the PAX8 mutation contributes to the phenotype needs to be further investigated. We recommend to screen patients with CH and TD for mutations in all known TD candidate genes.

Heterogeneity of lung disease associated with NK2 homeobox 1 mutations.

We retrospectively studied the clinical presentation, treatment modalities and outcome in 16 patients with heterozygous NKX2-1 mutation associated with chronic lung disease. Twelve different NKX2-1 mutations, including 4 novel mutations, were identified in the 16 patients. Nine patients presented with brain-lung-thyroid syndrome, 3 had neurological and lung symptoms and 4 had only pulmonary symptoms. Ten patients had neonatal respiratory distress, and 6 of them developed infiltrative lung disease (ILD). The other patients were diagnosed with ILD in childhood (n = 3) or in adulthood (n = 3). The median age at diagnosis was 36 months (IQ 3.5-95). Patient testing included HRCT (n = 13), BALF analysis (n = 6), lung biopsies (n = 3) and lung function tests (n = 6). Six patients required supplemental oxygen support with a median duration of 18 months (IQ 2.5-29). All symptomatic ILD patients (n = 12) benefited from a treatment consisting of steroids, azithromycin (n = 9), and/or hydroxychloroquine (n = 4). The median follow-up was 36 months (IQ 24-71.5). One patient died of respiratory failure at 18 months and another is waiting for lung transplantation. In summary, the initial diagnosis was based on clinical presentation and radiological features, but the presentation was heterogeneous. Definitive diagnosis required genetic analysis, which should be performed, even in absence of neurological or thyroid symptoms.

A further case of brain-lung-thyroid syndrome with deletion proximal to NKX2-1.

Brain-lung-thyroid syndrome (OMIM #610978) is associated with mutations in the NK2 homeobox 1 (NKX2-1) gene, a transcription factor important in development. 50% of patients are affected by the full triad, comprising congenital hypothyroidism, benign hereditary chorea and infant respiratory distress syndrome. Four cases have previously been reported where a patient has features consistent with brain-lung-thyroid syndrome and a chromosome 14q13 deletion adjacent to, but not disrupting, NKX2-1. We present a patient who has a phenotype consistent with brain-lung-thyroid syndrome, featuring congenital hypothyroidism and choreoathetoid movements with gross motor delay. Thyroid ultrasound showed a small-normal gland and spontaneous resolution of hypothyroidism. Array CGH revealed a de novo 14q13.2-3 deletion adjacent to but not directly involving NKX2-1. Sequencing of NKX2-1 was normal. This report highlights a further case of chromosomal deletion adjacent to NXK2-1 in a patient with a phenotype consistent with brain-lung-thyroid syndrome, and confirms that array-CGH is a useful test in the investigation of congenital hypothyroidism. Deletion of the adjacent gene MBIP in most reported cases so far may be relevant to the pathogenesis of brain-lung-thyroid syndrome. Deletion of nearby promoter or enhancer elements acting on NKX2-1 could also be an important factor. However, further work is needed to elucidate the pathogenesis of the brain-lung-thyroid phenotype in such cases.

De novo p.Arg756Cys mutation of ATP1A3 causes an atypical form of alternating hemiplegia of childhood with prolonged paralysis and choreoathetosis.

BACKGROUND: Alternating hemiplegia of childhood (AHC) is a rare neurological disorder that manifests recurrent attacks of hemiplegia, oculogyric, and choreoathetotic involuntary movements. De novo mutations in ATP1A3 cause three types of neurological diseases: AHC; rapid-onset dystonia-Parkinsonism (RDP); and cerebellar ataxia, areflexia, pes cavus, optic atrophy, and sensorineural hearing loss (CAPOS) syndromes. It remains to be determined whether or not a rare mutation in ATP1A3 may cause atypical phenotypes. CASE PRESENTATION: A 7-year-old boy presented with recurrent symptoms of generalized paralysis since 1 year and 5 months of age. Hypotonia, dystonia, and choreoathetosis persisted with exacerbation under febrile conditions, but no cerebellar ataxia had ever evolved in 6 years. Whole-exome sequencing (WES) was performed to determine his genetic background, and mutations were validated by the Sanger method. Crude protein extracts were prepared from the cultured cells, and expression of the wild-type or mutant ATP1A3 proteins were analyzed by Western blotting. WES identified a de novo pathogenic mutation in ATP1A3 (c.2266C > T:p.R756C) for this patient. A literature overview of two reported cases with p.R756C and p.R756H mutations showed both overlapping and distinct phenotypes when compared with those of the present case. The expression of the mutant form (R756C) of ATP1A3 did not differ markedly from that of the wild-type and D801N proteins. CONCLUSIONS: This study confirmed that p.R756C mutation of ATP1A3 cause atypical forms of AHC-associated disorders. The wide spectra of neurological phenotypes in AHC are linked to as-yet-unknown deficits in the functions of mutant ATP1A3.

Infantile epileptic encephalopathy, transient choreoathetotic movements, and hypersomnia due to a De Novo missense mutation in the SCN2A gene.

Mutations of the SCN2A gene have originally been described in association with benign familial neonatal-infantile seizures (BFNIS). Recently, single patients with more severe phenotypes and persisting epileptic encephalopathies have been recognized. We report the case of a girl with severe infantile onset epileptic encephalopathy and a de novo missense mutation in the SCN2A gene (c.4025T > C/ = ; p.L1342P/ = ), who presented with a transient choreatic movement disorder, hypersomnia, and progressive brain atrophy. Whole exome sequencing did not reveal any other disease causing mutation. Our patient contributes to the expanding phenotypic spectrum of SCN2A-related disorders and underlines the importance of genetic workup in epileptic encephalopathies.

A novel mutation of NKX2-1 affecting 2 generations with hypothyroidism and choreoathetosis: part of the spectrum of brain-thyroid-lung syndrome.

The NKX2-1 (TTF-1 or TITF-1) gene on chromosome 14q13 codes for the thyroid transcription factor 1 (TTF-1). It is expressed in the developing brain, lung, and thyroid. Defects have been associated with chorea, hypothyroidism, and lung disease, comprising the "brain-thyroid-lung syndrome." We describe here 3 cases of novel missense mutation (c.626G>C; p.Arg209Pro) in NKX2-1 in 2 generations of a nonconsanguinous family. Firstly 2 sons were affected by childhood-onset hypothyroidism and a movement disorder characterized by ataxia in the early years followed by the emergence of a superimposed chorea. The mutation was also found in the granddaughter, when she presented with the same clinical features. We hypothesize that the mutation arose as a result of gonadal mosaicism, as the mutation was not detected in leucocyte DNA from either grandparent. The features are consistent with a diagnosis of Brain-thyroid-lung syndrome, which previously could have been classified as benign hereditary chorea with hypothyroidism.

NKX2-1 mutations in brain-lung-thyroid syndrome: a case series of four patients.

Brain-lung-thyroid syndrome (BLTS) characterized by congenital hypothyroidism, respiratory distress syndrome, and benign hereditary chorea is caused by thyroid transcription factor 1 (NKX2-1/TTF1) mutations. We report the clinical and molecular characteristics of four cases presenting with primary hypothyroidism, respiratory distress, and neurological disorder. Two of the four patients presenting with the triad of BLTS had NKX2-1 mutations, and one of these NKX2-1 [c.890_896del (p.Ala327Glyfs*52)] is a novel variant. The third patient without any identified NKX2-1 mutations was a carrier of mitochondrial mutation; this raises the possibility of mitochondrial mutations contributing to thyroid dysgenesis. Although rare, the triad of congenital hypothyroidism, neurological, and respiratory signs is highly suggestive of NKX2-1 anomalies. Screening for NKX2-1 mutations in patients with thyroid, lung, and neurological abnormalities will enable a unifying diagnosis and genetic counseling for the affected families. In addition, identification of an NKX2-1 defect would be helpful in allaying the concerns about inadequate thyroxine supplementation as the cause of neurological defects observed in some children with congenital hypothyroidism.