Gait disturbance in a patient with de novo 1.0-kb SOX2 microdeletion

BACKGROUND

Sex-determining region Y-box 2 (SOX2) plays an important role in the early embryogenesis of the eye, forebrain, and hypothalamic-pituitary axis. Anophthalmia, microphthalmia, and hormonal abnormalities are commonly observed in patients with SOX2-related disorders. Although gait disturbance, particularly ataxic gait, has recently been observed in several cases, detailed data regarding the clinical course of gait disturbance in SOX2-related disorders are limited.

CASE REPORT

A 9-year-old Japanese boy presented with focal dyskinesia only during walking and running after he started walking at the age of 3 years. He also exhibited intellectual disability and mild dysmorphic features, including microcephaly, micropenis, and short stature associated with hormonal abnormalities. Gait disturbance with involuntary extremity movements only during walking and running was indicative of choreoathetosis and dystonia. Genetic analysis detected a de novo heterozygous 1.0-kb deletion including SOX2 at 3q26.32, as described in a previous technical paper.

CONCLUSIONS

SOX2-related disorders should be considered in patients with some anomalies having a differential diagnosis of dyskinesia. Focal dyskinesia only during walking and running may be a characteristic feature of SOX2-related disorders.

Choreoathetosis in the Setting of Human Herpesvirus-6 Infection in a Transplant Recipient

Background:

Human herpesvirus-6 (HHV-6) has been associated with various neurologic disorders, but movement disorders are rare. This case describes a patient who developed a choreoathetotic movement disorder in the setting of HHV-6 infection.

Case Report:

A 72-year-old woman with AML and recent HHV-6 encephalitis following stem cell transplant presented with involuntary movements. Neurologic examination demonstrated motor impersistence and irregular non-stereotyped writhing movements consistent with a choreoathetotic movement disorder secondary to HHV-6 infection.

Discussion:

This is the first literature reported case of adult-onset chorea associated with HHV-6 infection, though it remains unclear if the movement disorder was from the infection or a secondary autoimmune response.

Cerebral Venous Sinus Thrombosis in a Child with Lesch-Nyhan Syndrome

Lesch-Nyhan syndrome is a rare neurometabolic condition characterized by progressive choreoathetosis, intellectual disability, and peculiar manifestations like self-mutilation. Occasional case reports in adults have suggested an association between Lesch-Nyhan syndrome and hypercoagulability; however, no such report of either a venous or arterial stroke in children with Lesch-Nyhan Syndrome exists in literature. We present a 3-year-old boy with global developmental delay, dystonic posturing, choreoathetoid movements, and self-mutilation involving fingers and lips. He had acute worsening of sensorium, recurrent seizures, and opisthotonous posturing. A diagnosis of Lesch-Nyhan Syndrome was confirmed by extremely low hypoxanthine-guanine phosphoribosyltransferase enzyme levels. In view of an acute neurological deterioration, magnetic resonance imaging brain and magnetic resonance venogram were done that showed sagittal and left transverse venous sinus thrombosis. This case is the first case report of cerebral venous sinus thrombosis in a child with Lesch-Nyhan Syndrome. It further strengthens the association between hypercoagulability and Lesch-Nyhan syndrome.

Crossed Choreoathetosis Caused by Unilateral Thalamic Hemorrhage

In general, involuntary movements after stroke are due to a disturbance in the unilateral cortico-basal ganglia loop and appear contralateral to stroke lesions. Crossed involuntary movements after unilateral stroke are very rare. We observed a case of crossed involuntary movements in the left upper limb and right lower limb after a right thalamic hemorrhage expanded to the right subthalamic nucleus. We considered a possible three-step theory as the basis of crossed choreoathetosis. This case informs our better understanding of the cortico-basal ganglia loop and involuntary movements after stroke.

Hyperbilirubinemia and Asphyxia in Children With Dyskinetic Cerebral Palsy

BACKGROUND

We aimed to study the clinical, etiologic, and radiological characteristics in children with dyskinetic cerebral palsy (DCP) and to compare the etiologic subtypes of hyperbilirubinemia and perinatal asphyxia.

METHODS

This is a cross-sectional, observational study that enrolled consecutive children with DCP, aged one to 14 years.

RESULTS

Sixty-five children with DCP were evaluated. Most children were boys (77%, n = 50), and term gestation (80%, n = 52). Presenting concerns were global developmental delay (97%, n = 63) and involuntary movements (60%, n = 39). Hyperbilirubinemia (66%, n = 43) and perinatal asphyxia (29%, n = 19) were the most important causes. The majority (83%, n = 54) of children were severely disabled (level V and IV). The hyperbilirubinemia group had significant motor delay (63% vs 37%, P = 0.03) and upward gaze palsy (69.7% vs 31.5%, P = 0.005) when compared with the perinatal asphyxia group. Hyperbilirubinemia significantly involved pallidi (86% vs 10% P = 0.0001) and subthalamic nucleus (26% vs none, P = 0.01), whereas asphyxia significantly involved the putamen (58% vs none, P = 0.0001), thalamus (63% vs none, P = 0.0001), and periventricular white matter (79% vs 19%, P = 0.0001).

CONCLUSIONS

DCP is the dominant type of cerebral palsy seen in term-born babies with severe dystonia, developmental delay, and motor impairment. Hyperbilirubinemia is the major cause of DCP in the study. Hyperbilirubinemia is associated with motor delay, upward gaze palsy, prominent dystonia, and involvement of globus pallidi and subthalamic nuclei.

Clinical and molecular findings in a Turkish family with an ultra-rare condition, ELP2-related neurodevelopmental disorder

Elongator is a multi-subunit protein complex bearing six different protein subunits, Elp1 to -6, that are highly conserved among eukaryotes. Elp2 is the second major subunit of Elongator and, together with Elp1 and Elp3, form the catalytic core of this essential complex. Pathogenic variants that affect the structure and function of the Elongator complex may cause neurodevelopmental disorders. Here, we report on a new family with three children affected with a severe form of intellectual disability along with spastic tetraparesis, choreoathetosis, and self injury. Molecular genetic analyses reveal a homozygous missense variant in the ELP2 gene (NM_018255.4 (ELP2): c.1385G > A (p.Arg462Gln)), while in silico studies suggest a loss of electrostatic interactions that may contribute to the overall stability of the encoded protein. We also include a comparison of the patients with ELP2-related neurodevelopmental disorder to those previously reported in the literature. Apart from being affected with intellectual disability, we have extremely limited clinical knowledge about patients harboring ELP2 variants. Besides providing support to the causal role of p.Arg462Gln in ELP2-related neurodevelopmental disorder, we add self-injurious behavior to the clinical phenotypic repertoire of the disease.

Dystonia and choreoathetosis presence and severity in relation to powered wheelchair mobility performance in children and youth with dyskinetic cerebral palsy

INTRODUCTION

Power wheelchairs (PW) with head/foot steering systems are used as an alternative to joysticks in children with severe dyskinetic cerebral palsy (DCP). Mobility training programs are unstandardized to date, and insight on dystonia, choreoathetosis, and mobility performance may lead to greater independent mobility.

OBJECTIVE

To map the presence and severity of dystonia and choreoathetosis during PW mobility in DCP and their relation with mobility performance.

METHODS

Ten participants with DCP performed four PW mobility tasks using a head/foot steering system. Dystonia and choreoathetosis in the neck and arm regions were evaluated using the Dyskinesia Impairment Mobility Scale (DIMS). PW mobility performance was assessed using time-on-task and the number of errors during performance. The Wilcoxon-signed rank test and the Spearman's correlation coefficients were used to explore differences and correlations.

RESULTS

Median levels of dystonia (83.6%) were significantly higher (p < 0.01) than median levels of choreoathetosis (34.4%). Positive significant correlations were found between the Arm Proximal DIMS and the PW mobility experience (r_s=-0.92, p < 0.001), and between the Arm Distal DIMS and the number of errors (r_s = 0.66, p = 0.039) during mobility performance.

CONCLUSIONS

Dystonia is more present and severe during PW mobility than choreoathetosis. The hypertonic hallmark of dystonia may mask the hyperkinetic hallmark of choreoathetosis, resulting in lower median levels. Results may suggest that with an increase in driving experience, children with DCP adopt deliberate strategies to minimize the negative impact of arm overflow movements on mobility performance, however, future research with bigger sample size and additional outcome measures is strongly encouraged.

Zonisamide Therapy for Patients With Paroxysmal Kinesigenic Dyskinesia

BACKGROUND

We evaluated zonisamide therapy in patients with paroxysmal kinesigenic dyskinesia (PKD).

METHODS

We analyzed zonisamide therapy in 17 patients with PKD at Saitama Children's Medical Center between November 1994 and April 2020. We collected information regarding family history, previous history, age at onset, age at zonisamide commencement, dyskinesia characteristics, brain magnetic resonance imaging, interictal electroencephalography, treatment lag, zonisamide efficacy, zonisamide dose, serum zonisamide concentration, and adverse effects. We evaluated PKD frequency at six months after zonisamide therapy commencement.

RESULTS

Fourteen patients met the inclusion criteria. The median age at zonisamide therapy commencement was 12.8 (9.4 to 16.3) years. Zonisamide therapy was effective in 13 of 14 (92.9%) patients: complete remission for more than three months after zonisamide therapy (n = 7), decreased dyskinesia frequency by more than 90% (n = 4), dyskinesia frequency by 75% to 90% (n = 2), and no change of dyskinesia frequency (n = 1). The initial and maintenance zonisamide doses were 2.0 (1.4 to 3.8) and 2.0 (1.5 to 5.9) mg/kg/day, respectively. The median duration between zonisamide therapy commencement and dyskinesia decrease or cessation was 4 (1 to 60) days: 10 of 14 (71.4%) patients responded to zonisamide within one week after zonisamide therapy commencement. Regarding adverse effects, two patients experienced somnolence and one developed reduced perspiration.

CONCLUSIONS

We suggest that zonisamide monotherapy is effective for patients with PKD as a first-line treatment. We can evaluate the efficacy of zonisamide therapy within one week. Because zonisamide lacks the enzyme-inducing effects of carbamazepine and phenytoin, it may be useful for PKD treatment.

Instrumented assessment of motor function in dyskinetic cerebral palsy: a systematic review

BACKGROUND

In this systematic review we investigate which instrumented measurements are available to assess motor impairments, related activity limitations and participation restrictions in children and young adults with dyskinetic cerebral palsy. We aim to classify these instrumented measurements using the categories of the international classification of functioning, disability and health for children and youth (ICF-CY) and provide an overview of the outcome parameters.

METHODS

A systematic literature search was performed in November 2019. We electronically searched Pubmed, Embase and Scopus databases. Search blocks included (a) cerebral palsy, (b) athetosis, dystonia and/or dyskinesia, (c) age 2-24 years and (d) instrumented measurements (using keywords such as biomechanics, sensors, smartphone, and robot).

RESULTS

Our search yielded 4537 articles. After inspection of titles and abstracts, a full text of 245 of those articles were included and assessed for further eligibility. A total of 49 articles met our inclusion criteria. A broad spectrum of instruments and technologies are used to assess motor function in dyskinetic cerebral palsy, with the majority using 3D motion capture and surface electromyography. Only for a small number of instruments methodological quality was assessed, with only one study showing an adequate assessment of test-retest reliability. The majority of studies was at ICF-CY function and structure level and assessed control of voluntary movement (29 of 49) mainly in the upper extremity, followed by assessment of involuntary movements (15 of 49), muscle tone/motor reflex (6 of 49), gait pattern (5 of 49) and muscle power (2 of 49). At ICF-CY level of activities and participation hand and arm use (9 of 49), fine hand use (5 of 49), lifting and carrying objects (3 of 49), maintaining a body position (2 of 49), walking (1 of 49) and moving around using equipment (1 of 49) was assessed. Only a few methods are potentially suitable outside the clinical environment (e.g. inertial sensors, accelerometers).

CONCLUSION

Although the current review shows the potential of several instrumented methods to be used as objective outcome measures in dyskinetic cerebral palsy, their methodological quality is still unknown. Future development should focus on evaluating clinimetrics, including validating against clinical meaningfulness. New technological developments should aim for measurements that can be applied outside the laboratory.

Clinical and biochemical footprints of inherited metabolic diseases. I. Movement disorders

About a third of patients with inherited metabolic diseases with neurologic involvement suffer from a movement disorder, in the form of ataxia, hyperkinetic movements, or hypokinetic-rigid syndrome. We reviewed and updated the list of known metabolic etiologies associated with various types of movement disorders, and found approximately 200 relevant inborn errors of metabolism. This represents the first of a series of articles attempting to create and maintain a comprehensive list of clinical and metabolic differential diagnoses according to system involvement.

Recessive mutations in ATP8A2 cause severe hypotonia, cognitive impairment, hyperkinetic movement disorders and progressive optic atrophy

Background

ATP8A2 mutations have recently been described in several patients with severe, early-onset hypotonia and cognitive impairment. The aim of our study was to characterize the clinical phenotype of patients with ATP8A2 mutations.

Methods

An observational study was conducted at multiple diagnostic centres. Clinical data is presented from 9 unreported and 2 previously reported patients with ATP8A2 mutations. We compare their features with 3 additional patients that have been previously reported in the medical literature.

Results

Eleven patients with biallelic ATP8A2 mutations were identified, with a mean age of 9.4 years (range 2.5–28 years). All patients with ATP8A2 mutations (100%) demonstrated developmental delay, severe hypotonia and movement disorders, specifically chorea or choreoathetosis (100%), dystonia (27%) and facial dyskinesia (18%). Optic atrophy was observed in 78% of patients for whom funduscopic examination was performed. Symptom onset in all (100%) was noted before 6 months of age, with 70% having symptoms noted at birth. Feeding difficulties were common (91%) although most patients were able to tolerate pureed or thickened feeds, and 3 patients required gastrostomy tube insertion. MRI of the brain was normal in 50% of the patients. A smaller proportion was noted to have mild cortical atrophy (30%), delayed myelination (20%) and/or hypoplastic optic nerves (20%). Functional studies were performed on differentiated induced pluripotent cells from one child, which confirmed a decrease in ATP8A2 expression compared to control cells.

Conclusions

ATP8A2 gene mutations have emerged as the cause of a novel neurological phenotype characterized by global developmental delays, severe hypotonia and hyperkinetic movement disorders, the latter being an important distinguishing feature. Optic atrophy is common and may only become apparent in the first few years of life, necessitating repeat ophthalmologic evaluation in older children. Early recognition of the cardinal features of this condition will facilitate diagnosis of this complex neurologic disorder.

Electronic supplementary material

The online version of this article (10.1186/s13023-018-0825-3) contains supplementary material, which is available to authorized users.

Movement disorders in mitochondrial disease

Mitochondrial disease presents with a wide spectrum of clinical manifestations that may appear at any age and cause multisystem dysfunction. A broad spectrum of movement disorders can manifest in mitochondrial diseases including ataxia, Parkinsonism, myoclonus, dystonia, choreoathetosis, spasticity, tremor, tic disorders and restless legs syndrome. There is marked heterogeneity of movement disorder phenotypes, even in patients with the same genetic mutation. Moreover, the advent of new technologies, such as next-generation sequencing, is likely to identify novel causative genes, expand the phenotype of known disease genes and improve the genetic diagnosis in these patients. Identification of the underlying genetic basis of the movement disorder is also a crucial step to allow for targeted therapies to be implemented as well as provide the basis for a better understanding of the molecular pathophysiology of the disease process. The aim of this review is to discuss the spectrum of movement disorders associated with mitochondrial disease.

Choreoathetosis - an unusual adverse effect of dihydroartemisinin-piperaquine: a case report

Background

Dihydroartemisinin-piperaquine is a combination of dihydroartemisinin and piperaquine which is highly effective in the treatment of uncomplicated falciparum malaria. Its adverse effects are generally tolerable and temporary. Choreoathetosis, an involuntary movement disorder characterized by continuous irregular twisting of the body, is not a documented adverse effect of this medication.

Case presentation

A 41-year-old Cameroonian man of black African ethnicity was brought to our primary care hospital because over the previous 6 hours he had been experiencing involuntary twisting movements of his body and he no longer had control of his limbs. Earlier that day, he had been prescribed an appropriate dose of dihydroartemisinin-piperaquine in our hospital. The abnormal movements started approximately 3 hours after ingesting the first dose of the drug. The review of systems and his past history were unremarkable. On clinical examination, he was conscious and oriented but was unsteady and displayed continuous generalized irregular twisting movements combined with abrupt low amplitude flinging of his limbs. Dihydroartemisinin-piperaquine-induced generalized choreoathetosis was diagnosed. He was sedated with diazepam and dihydroartemisinin-piperaquine was discontinued. The antimalarial drug was substituted with artemether-lumefantrine combination. The clinical progress was good and he was discharged home after 72 hours. No further abnormalities were noted during 7 months of follow-up.

Conclusion

Although dihydroartemisinin-piperaquine is increasingly popular as a well-tolerated/efficacious antimalarial drug, clinicians must note the rare possibility of choreoathetosis as an adverse effect of this medication and educate patients accordingly.

Choreoathetosis Is a Possible Adverse Event of a Commonly Used Antibiotic

BACKGROUND

Choreoathetosis (CAS) is attributed to a few neuropsychiatric drugs; however, it is scarcely reported with commonly used antibiotics.

AIMS

To present a case of ceftriaxone (CTX)-induced CAS and to perform a literature review.

SETTING

A medical teaching hospital.

CASE HISTORY

An 83-year-old female with end stage renal disease was prescribed CTX 2 g/day intravenously and doxycycline (DXC) 200 mg/day orally for the treatment of acute community-acquired systemic infection. CAS developed 3 days after the administration of both drugs. Withdrawal of CTX and DXC yielded complete resolution of the CAS on the following day. Neither neurological adverse events related to DXC use nor pharmacological interaction between DXC and CTX was reported. Therefore, the CAS development was attributed to CTX.

CONCLUSION

CTX as well as other ß-lactam antibiotics induce glutamate excess in the striatum and cerebral cortex, resulting in neurological hyperexcitability disorders. Dosage adjustment of these antibiotics in relation to the patients' renal clearance is warranted.

The relationship of dystonia and choreoathetosis with activity, participation and quality of life in children and youth with dyskinetic cerebral palsy

AIM

To relate dystonia and choreoathetosis with activity, participation and quality of life (QOL) in children and youth with dyskinetic Cerebral Palsy (CP).

METHODS

Fifty-four participants with dyskinetic CP (mean age 14y6m, SD 4y2m, range 6-22y) were included. The Dyskinesia Impairment Scale (DIS) was used to evaluate dystonia and choreoathetosis. Activity, participation and quality of life (QOL) were assessed with the Gross Motor Function Measure (GMFM), the Functional Mobility Scale (FMS), the Jebsen-Taylor Hand Function Test (JTT), the ABILHAND-Kids Questionnaire (ABIL-K), the Life Habits Kids (LIFE-H) and the Quality of Life Questionnaire for children with CP (CP-QOL). Spearman's rank correlation coefficient (r_s) was used to assess the relationship between the movement disorders and activity, participation and QOL measures.

RESULTS

Significant negative correlations were found between dystonia and the activity scales with Spearman's rank correlation coefficient (r_s) varying between -0.65 (95% CI = -0.78 to -0.46) and -0.71 (95% CI = -0,82 to -0.55). Correlations were also found with the LIFE-H (r_s = -0.43; 95%CI = -0.64 to -0.17) and the CP-QOL (r_s = -0.32; 95%CI = -0.56 to -0.03). As far as choreoathetosis is concerned, no or only weak relationships were found with the activity, participation and quality of life scales.

INTERPRETATION

This cross-sectional study is the first to examine the relationship of dystonia and choreoathetosis in dyskinetic CP with the level of activity, participation and QOL. The results revealed dystonia has a higher impact on activity, participation and quality of life than choreoathetosis. These findings seem to suggest it is necessary to first focus on dystonia reducing intervention strategies and secondly on choreoathetosis.

Glutaric Aciduria Type I: A Rare Metabolic Disorder Mimicking as Choreoathetoid Cerebral Palsy

Glutaric aciduria type I (GA I) is an autosomal recessive inborn error of metabolism caused by a deficiency of the enzyme glutaryl-CoA dehydrogenase. This disorder is characterized by progressive dystonia, choreoathetosis, and dyskinesia. It is often misdiagnosed as athetoid cerebral palsy. Laboratory evaluation usually demonstrates increased urinary excretion of gluataric acid and 3-hydroxyglutaric acid. We report a case of a 7-year-old boy presenting with choreoathetosis and dystonia, mimicking as choreoathetoid cerebral palsy. The presence of characteristic neuroimaging and biochemical studies led to the diagnosis of GA I.

More Than Ataxia: Hyperkinetic Movement Disorders in Childhood Autosomal Recessive Ataxia Syndromes

Background

The autosomal recessive ataxias are a heterogeneous group of disorders that are characterized by complex neurological features in addition to progressive ataxia. Hyperkinetic movement disorders occur in a significant proportion of patients, and may sometimes be the presenting motor symptom. Presentations with involuntary movements rather than ataxia are diagnostically challenging, and are likely under-recognized.

Methods

A PubMed literature search was performed in October 2015 utilizing pairwise combinations of disease-related terms (autosomal recessive ataxia, ataxia–telangiectasia, ataxia with oculomotor apraxia type 1 (AOA1), ataxia with oculomotor apraxia type 2 (AOA2), Friedreich ataxia, ataxia with vitamin E deficiency), and symptom-related terms (movement disorder, dystonia, chorea, choreoathetosis, myoclonus).

Results

Involuntary movements occur in the majority of patients with ataxia–telangiectasia and AOA1, and less frequently in patients with AOA2, Friedreich ataxia, and ataxia with vitamin E deficiency. Clinical presentations with an isolated hyperkinetic movement disorder in the absence of ataxia include dystonia or dystonia with myoclonus with predominant upper limb and cervical involvement (ataxia–telangiectasia, ataxia with vitamin E deficiency), and generalized chorea (ataxia with oculomotor apraxia type 1, ataxia-telangiectasia).

Discussion

An awareness of atypical presentations facilitates early and accurate diagnosis in these challenging cases. Recognition of involuntary movements is important not only for diagnosis, but also because of the potential for effective targeted symptomatic treatment.

Atypical presentation of Costeff syndrome-severe psychomotor involvement and electrical status epilepticus during slow wave sleep

BACKGROUND

Costeff syndrome or OPA3-related 3-methylglutaconic aciduria is an autosomal recessive neurodegenerative disorder characterized by early onset optic atrophy and choreoathetosis with later onset of ataxia and spasticity. Costeff syndrome is prevalent among Iraqi Jews.

METHODS

We describe a 5 year old girl from Syrian Jewish origin with an atypical presentation of Costeff syndrome.

RESULTS

The patient presented with asymmetric optic atrophy, severe dystonia and choreoathetosis and global developmental regression at the age of 7 months; no achievement of independent walking and only minimal speech; and appearance of electrical status epilepticus during slow wave sleep in the second year of life with further deterioration. She harbors the classic mutation (c.143-1G > C) in the OPA3 gene.

CONCLUSION

Costeff syndrome may present in an atypical manner regarding the ethnic origin, clinical manifestations and co-occurrence of epilepsy. Mutations in OPA3 should be evaluated in all cases presenting with the core features of typical Costeff syndrome.

Novel NKX2-1 Frameshift Mutations in Patients with Atypical Phenotypes of the Brain-Lung-Thyroid Syndrome

OBJECTIVES

To verify the involvement of NKX2-1 gene in infants with brain-lung-thyroid (BLT) syndrome and hypothyroid phenotypes variable among congenital hypothyroidism (CH) or idiopathic mild hypothyroidism (IMH) of postnatal onset.

METHODS

The candidates were selected by a case-finding approach in 130 CH and 53 IMH infants. The NKX2-1 gene was analyzed by direct sequencing and multiplex ligation-dependent probe amplification. The variants were studied in vitro, by expression analyses and luciferase bioassay.

RESULTS

Four cases (3 CH and 1 IMH) consistent with BLT syndrome were identified. Two children were affected with respiratory distress and CH, but wild-type NKX2-1 gene. The remaining two presented choreic movements and no pulmonary involvement, but discrepant thyroid phenotypes: one had severe CH with lingual ectopy and the other one IMH with gland in situ. They were carriers of new de novo heterozygous frameshift mutations of NKX2-1 (c.177delG and c.153_166del14). The c.177delG leads to a prematurely truncated protein (p.H60TfsX11) with undetectable activity in vitro. The c.153_166del14 leads to the generation of an elongated aberrant protein (p.A52RfsX351) able to translocate into the nucleus, but completely inactive on a responsive promoter.

CONCLUSIONS

Two novel heterozygous frameshift mutations of NKX2-1 were identified in 2 cases selected on the basis of a BLT-like phenotype among 183 hypothyroid infants. The atypical hypothyroid phenotypes of these 2 children (CH with lingual ectopy or IMH of postnatal onset) further expand the clinical spectrum that can be associated with NKX2-1 mutations.