Development of GO Move: A Website for Children With Unilateral Cerebral Palsy.

It is unknown if an online tool is wanted by therapists and parents of individuals with unilateral cerebral palsy (UCP) to support implementation of goal-directed home programs, and if wanted, the recommended features for the tool. The objective was to explore the experiences of therapists and parents who have implemented home programs, seek guidance on translating a paper-based home program toolbox into a mobile website, and develop the website. Qualitative descriptive methodology guided data collection using semi-structured interviews and thematic analysis, validated with field notes and member checking. A team science, iterative approach was used to integrate the themes into the development of the mobile website. Five primary themes including recommendations for the functionality, features, content, and naming of the mobile website were identified. Parents and therapists value home programs. Participants provided recommendations regarding content and features, and the GO Move mobile website was developed based on the recommendations.

Development of Go Move: A Website for Children With Unilateral Cerebral PalsyTherapists and parents of children with unilateral cerebral palsy were interviewed to understand their experience of home programs and gain input for creating a mobile website with information on goal setting and implementing home programs. The interviews provided valuable information about the functionality, features, content, and naming of the website. GO Move, a mobile website aimed to provide information on goal setting, activity selection, and tracking of exercises and activities in the home environment for children with unilateral cerebral palsy, was developed based on the information from the interviews.

Constraint Induced Movement Therapy Camp for Children with Hemiplegic Cerebral Palsy Augmented by Use of an Exoskeleton to Play Games in Virtual Reality.

AIM: To determine the acceptability and effects of a pediatric constraint induced movement therapy (P-CIMT) camp for children with hemiplegic cerebral palsy (hCP) augmented by use of an exoskeleton to play games in virtual reality (VR). METHOD: 31 children with hCP attended a P-CIMT camp 6 hours per day for 10 days over 2 successive weeks (60 hours) that included 30 minutes of unilateral training with the Hocoma Armeo®Spring Pediatric that combines the assistance of an exoskeleton and VR games. The primary outcome measure was the Assisting Hand Assessment (AHA); secondary outcome measures were the Melbourne Assessment of Uni-lateral Hand Function (MUUL), and the Canadian Occupational Performance Measure (COPM). Assessments were completed at pre-intervention, post-intervention, and 6 months following intervention. RESULTS: Participants demonstrated clinically and statistically significant improvement in bimanual performance (AHA) (p < .001) and COPM Performance (p < .001) and Satisfaction with performance (p < .001). Improvement in unilateral performance (MUUL) was statistically (p < .001) but not clinically significant. CONCLUSIONS: A P-CIMT camp augmented by the Hocoma Armeo®Spring Pediatric was feasible and accepted by participants. Bimanual hand function and occupational performance improved immediately following intervention, and the treatment effects persisted 6 months following intervention.

Neural and non-neural contributions to ankle spasticity in children with cerebral palsy.

AIM: To assess the neural and non-neural contributions to spasticity in the impaired ankle of children with cerebral palsy (CP). METHOD: Instrumented tapping of the Achilles tendon was done isometrically to minimize non-neural contributions and elicit neural contributions. Robot-controlled ankle stretching was done at various velocities, including slow stretching, with minimized neural contributions. Spasticity was assessed as having neural (phasic and tonic stretch reflex torque, tendon reflex gain, contraction rate, and half relaxation rate) and non-neural origin (elastic stiffness and viscous damping) in 17 children with CP (six females and 11 males; mean age [SD] 10y 8mo [3y 11mo], range 4y-18y) and 17 typically developing children (six females and 11 males; mean age [SD] 12y 7mo [2y 9mo], range 7y-18y). All torques were normalized to weight×height. RESULTS: Children with CP showed increased phasic and tonic stretch reflex torque (p=0.004 and p=0.001 respectively), tendon reflex gain (p=0.02), contraction rate (p=0.038), half relaxation rate (p=0.02), elastic stiffness (p=0.01), and viscous damping (p=0.01) compared to typically developing children. INTERPRETATION: Controlled stretching and instrumented tendon tapping allow the systematic quantification of various neural and non-neural changes in CP, which can be used to guide impairment-specific treatment. WHAT THIS PAPER ADDS: Ankle spasticity is associated with increased phasic and tonic stretch reflexes, tendon reflex gain, and contraction and half relaxation rates. Ankle spasticity is also associated with increased elastic stiffness and viscous damping.

Contribuciones neuronales y no neuronales a la espasticidad del tobillo en niños con parálisis cerebral OBJETIVO: Evaluar las contribuciones neurales y no neurales a la espasticidad en el tobillo comprometido de niños con parálisis cerebral (PC). MÉTODO: La percusión instrumentada en el tendón de Aquiles se realizó de forma isométrica para minimizar las contribuciones no neurales y un tirón del tendón exagerado, para obtener contribuciones neurales. El estiramiento del tobillo controlado por robot se realizó a varias velocidades, incluido el estiramiento lento, con contribuciones neurales minimizadas. Se evaluó la espasticidad como neural (torque reflejo de estiramiento fásico y tónico, ganancia del reflejo tendinoso, tasa de contracción y media tasa de relajación) y origen no neural (rigidez elástica y amortiguación viscosa) en 17 niños con PC (seis mujeres y 11 varones; edad media [DE] 10a 8m [3a 11m], rango 4a-18a) y 17 niños con desarrollo típico (seis mujeres y 11 hombres; edad media [SD] 12a 7m [2a 9m], rango 7a-18a). Todos los pares de torsion se normalizaron al peso × altura. RESULTADOS: Los niños con PC mostraron un aumento del torque reflejo de estiramiento fásico y tónico (p = 0,004 y p = 0,001 respectivamente), ganancia refleja del tendón (p = 0,02), tasa de contracción (p = 0,038), tasa de relajación media (p = 0,02), rigidez elastica (p = 0,01) y amortiguación viscosa (p = 0,01) en comparación con los niños con desarrollo normal. INTERPRETACIÓN: El estiramiento controlado y la percusión instrumentada del tendón, permiten la cuantificación sistemática de varios cambios neuronales y no neuronales en la PC, que pueden usarse para guiar el tratamiento específico de la discapacidad.

Contribuições neurais e não neurais para a espasticidade do tornozelo em crianças com paralisia cerebral OBJETIVO: Avaliar as contribuições neurais e não-neurais para a espasticidade no tornozelo comprometido de crianças com paralisia cerebral (PC). MÉTODO: O golpeamento instrumentalizado do tendão de Aquiles foi realizado isometricamente para minimizar as contribuições não-neurais e um desvio exagerado do tendão, e assim eliciar as contribuições neurais. O alongamento do tornozelo controlado por um robô foi realizado em várias velocidades, incluindo alongamento lento, com contribuições neurais limitadas. A espasticidade foi avaliada como tendo origem neural (torque do reflexo fásico e tônico, ganho do reflexo tendinoso, taxa de contração, e taxa de meio relaxamento) e não-neural (rigidez elástica e amortecimento viscoso) em 17 crianças com PC (seis do sexo feminino e 11 do sexo masculino; média de idade [DP] 10a 8m [3 11m], variação 4a-18a) e 17 crianças com desenvolvimento típico (seis do sexo feminino e 11 do sexo masculino; média de idade [DP] 12a 7m [2a 9m], variação 7a-18a). Todos os torques foram normalizados para peso x altura. RESULTADOS: Crianças com PC mostraram aumento do torque do reflexo tônico e fásico e (p=0,004 e p=0,001 respectivamente), ganho do reflexo tendinoso (p=0,02), taxa de contração (p=0,038), taxa de meio relaxamento (p=0,02), rigidez elástica (p=0,01), e amortecimento viscoso (p=0,01) em comparação com as crianças com desenvolvimento típico. INTERPRETAÇÃO: O alongamento controlado e o golpeamento instrumentalizado do tendão permitem quantificação sistemática de várias mudanças neurais e não-neurais em PC, as quais podem ser usadas para guiar tratamento específico para a deficiência observada.

Loss-of-Function Variants in PPP1R12A: From Isolated Sex Reversal to Holoprosencephaly Spectrum and Urogenital Malformations.

In two independent ongoing next-generation sequencing projects for individuals with holoprosencephaly and individuals with disorders of sex development, and through international research collaboration, we identified twelve individuals with de novo loss-of-function (LoF) variants in protein phosphatase 1, regulatory subunit 12a (PPP1R12A), an important developmental gene involved in cell migration, adhesion, and morphogenesis. This gene has not been previously reported in association with human disease, and it has intolerance to LoF as illustrated by a very low observed-to-expected ratio of LoF variants in gnomAD. Of the twelve individuals, midline brain malformations were found in five, urogenital anomalies in nine, and a combination of both phenotypes in two. Other congenital anomalies identified included omphalocele, jejunal, and ileal atresia with aberrant mesenteric blood supply, and syndactyly. Six individuals had stop gain variants, five had a deletion or duplication resulting in a frameshift, and one had a canonical splice acceptor site loss. Murine and human in situ hybridization and immunostaining revealed PPP1R12A expression in the prosencephalic neural folds and protein localization in the lower urinary tract at critical periods for forebrain division and urogenital development. Based on these clinical and molecular findings, we propose the association of PPP1R12A pathogenic variants with a congenital malformations syndrome affecting the embryogenesis of the brain and genitourinary systems and including disorders of sex development.

Cohesin complex-associated holoprosencephaly.

Marked by incomplete division of the embryonic forebrain, holoprosencephaly is one of the most common human developmental disorders. Despite decades of phenotype-driven research, 80-90% of aneuploidy-negative holoprosencephaly individuals with a probable genetic aetiology do not have a genetic diagnosis. Here we report holoprosencephaly associated with variants in the two X-linked cohesin complex genes, STAG2 and SMC1A, with loss-of-function variants in 10 individuals and a missense variant in one. Additionally, we report four individuals with variants in the cohesin complex genes that are not X-linked, SMC3 and RAD21. Using whole mount in situ hybridization, we show that STAG2 and SMC1A are expressed in the prosencephalic neural folds during primary neurulation in the mouse, consistent with forebrain morphogenesis and holoprosencephaly pathogenesis. Finally, we found that shRNA knockdown of STAG2 and SMC1A causes aberrant expression of HPE-associated genes ZIC2, GLI2, SMAD3 and FGFR1 in human neural stem cells. These findings show the cohesin complex as an important regulator of median forebrain development and X-linked inheritance patterns in holoprosencephaly.

In-depth investigations of adolescents and adults with holoprosencephaly identify unique characteristics.

PurposeWith improved medical care, some individuals with holoprosencephaly (HPE) are surviving into adulthood. We investigated the clinical manifestations of adolescents and adults with HPE and explored the underlying molecular causes.MethodsParticipants included 20 subjects 15 years of age and older. Clinical assessments included dysmorphology exams, cognitive testing, swallowing studies, ophthalmic examination, and brain magnetic resonance imaging. Genetic testing included chromosomal microarray, Sanger sequencing for SHH, ZIC2, SIX3, and TGIF, and whole-exome sequencing (WES) of 10 trios.ResultsSemilobar HPE was the most common subtype of HPE, seen in 50% of the participants. Neurodevelopmental disabilities were found to correlate with HPE subtype. Factors associated with long-term survival included HPE subtype not alobar, female gender, and nontypical facial features. Four participants had de novo pathogenic variants in ZIC2. WES analysis of 11 participants did not reveal plausible candidate genes, suggesting complex inheritance in these cases. Indeed, in two probands there was a history of uncontrolled maternal type 1 diabetes.ConclusionIndividuals with various HPE subtypes can survive into adulthood and the neurodevelopmental outcomes are variable. Based on the facial characteristics and molecular evaluations, we suggest that classic genetic causes of HPE may play a smaller role in this cohort.

Biallelic mutations in human DCC cause developmental split-brain syndrome.

Motor, sensory, and integrative activities of the brain are coordinated by a series of midline-bridging neuronal commissures whose development is tightly regulated. Here we report a new human syndrome in which these commissures are widely disrupted, thus causing clinical manifestations of horizontal gaze palsy, scoliosis, and intellectual disability. Affected individuals were found to possess biallelic loss-of-function mutations in the gene encoding the axon-guidance receptor 'deleted in colorectal carcinoma' (DCC), which has been implicated in congenital mirror movements when it is mutated in the heterozygous state but whose biallelic loss-of-function human phenotype has not been reported. Structural MRI and diffusion tractography demonstrated broad disorganization of white-matter tracts throughout the human central nervous system (CNS), including loss of all commissural tracts at multiple levels of the neuraxis. Combined with data from animal models, these findings show that DCC is a master regulator of midline crossing and development of white-matter projections throughout the human CNS.

Evaluation of cortical plasticity in children with cerebral palsy undergoing constraint-induced movement therapy based on functional near-infrared spectroscopy.

Sensorimotor cortex plasticity induced by constraint-induced movement therapy (CIMT) in six children (10.2±2.1 years old) with hemiplegic cerebral palsy was assessed by functional near-infrared spectroscopy (fNIRS). The activation laterality index and time-to-peak/duration during a finger-tapping task and the resting-state functional connectivity were quantified before, immediately after, and 6 months after CIMT. These fNIRS-based metrics were used to help explain changes in clinical scores of manual performance obtained concurrently with imaging time points. Five age-matched healthy children (9.8±1.3 years old) were also imaged to provide comparative activation metrics for normal controls. Interestingly, the activation time-to-peak/duration for all sensorimotor centers displayed significant normalization immediately after CIMT that persisted 6 months later. In contrast to this improved localized activation response, the laterality index and resting-state connectivity metrics that depended on communication between sensorimotor centers improved immediately after CIMT, but relapsed 6 months later. In addition, for the subjects measured in this work, there was either a trade-off between improving unimanual versus bimanual performance when sensorimotor activation patterns normalized after CIMT, or an improvement occurred in both unimanual and bimanual performance but at the cost of very abnormal plastic changes in sensorimotor activity.

Motion tracking and electromyography-assisted identification of mirror hand contributions to functional near-infrared spectroscopy images acquired during a finger-tapping task performed by children with cerebral palsy.

Recent studies have demonstrated functional near-infrared spectroscopy (fNIRS) to be a viable and sensitive method for imaging sensorimotor cortex activity in children with cerebral palsy (CP). However, during unilateral finger tapping, children with CP often exhibit unintended motions in the nontapping hand, known as mirror motions, which confuse the interpretation of resulting fNIRS images. This work presents a method for separating some of the mirror motion contributions to fNIRS images and demonstrates its application to fNIRS data from four children with CP performing a finger-tapping task with mirror motions. Finger motion and arm muscle activity were measured simultaneously with fNIRS signals using motion tracking and electromyography (EMG), respectively. Subsequently, subject-specific regressors were created from the motion capture or EMG data and independent component analysis was combined with a general linear model to create an fNIRS image representing activation due to the tapping hand and one image representing activation due to the mirror hand. The proposed method can provide information on how mirror motions contribute to fNIRS images, and in some cases, it helps remove mirror motion contamination from the tapping hand activation images.

Genotypic and phenotypic analysis of 396 individuals with mutations in Sonic Hedgehog.

BACKGROUND: Holoprosencephaly (HPE), the most common malformation of the human forebrain, may result from mutations in over 12 genes. Sonic Hedgehog (SHH) was the first such gene discovered; mutations in SHH remain the most common cause of non-chromosomal HPE. The severity spectrum is wide, ranging from incompatibility with extrauterine life to isolated midline facial differences. OBJECTIVE: To characterise genetic and clinical findings in individuals with SHH mutations. METHODS: Through the National Institutes of Health and collaborating centres, DNA from approximately 2000 individuals with HPE spectrum disorders were analysed for SHH variations. Clinical details were examined and combined with published cases. RESULTS: This study describes 396 individuals, representing 157 unrelated kindreds, with SHH mutations; 141 (36%) have not been previously reported. SHH mutations more commonly resulted in non-HPE (64%) than frank HPE (36%), and non-HPE was significantly more common in patients with SHH than in those with mutations in the other common HPE related genes (p<0.0001 compared to ZIC2 or SIX3). Individuals with truncating mutations were significantly more likely to have frank HPE than those with non-truncating mutations (49% vs 35%, respectively; p=0.012). While mutations were significantly more common in the N-terminus than in the C-terminus (including accounting for the relative size of the coding regions, p=0.00010), no specific genotype-phenotype correlations could be established regarding mutation location. CONCLUSIONS: SHH mutations overall result in milder disease than mutations in other common HPE related genes. HPE is more frequent in individuals with truncating mutations, but clinical predictions at the individual level remain elusive.

Holoprosencephaly in a family segregating novel variants in ZIC2 and GLI2.

Holoprosencephaly (HPE) is the most common malformation of the human forebrain. Typical manifestations in affected patients include a characteristic pattern of structural brain and craniofacial anomalies. HPE may be caused by mutations in over 10 identified genes; the inheritance is traditionally viewed as autosomal dominant with highly variable expressivity and incomplete penetrance. We present the description of a family simultaneously segregating two novel variants in the HPE-associated genes, ZIC2 and GLI2, as well as the results of extensive population-based studies of the variant region in GLI2. This is the first time that multiple HPE-associated variants in these genes have been reported in one family, and raises important questions about how clinicians and researchers should view the inheritance of conditions such as HPE.

Use of trihexyphenidyl in children with cerebral palsy.

A paucity of information exists regarding medications to treat dystonia in children with cerebral palsy. This study sought to review the benefits and tolerability of trihexyphenidyl in children with cerebral palsy, treated for dystonia or sialorrhea or both in a pediatric tertiary care hospital, through a retrospective chart review. In total, 101 patients (61 boys and 40 girls) were evaluated. The mean age at drug initiation was 7 years and 10 months (range, 1-18 years). The mean initial dose was 0.095 mg/kg/day. The dose was increased by 10-20% no sooner than every 2 weeks. The mean maximum dose reached was 0.55 mg/kg/day. Ninety-three patients (91%) tolerated the medication well, with a mean duration of treatment of 3 years and 7 months. Side effects occurred in 69% of subjects, the majority in patients aged ≥7 years, and soon after treatment initiation. Sixty-four percent continued the treatment at study end. Ninety-seven patients reported benefits, including reduction of dystonia in upper (59.4%) and lower (37.6%) extremities, sialorrhea (60.4%), and speech issues (24.7%). The majority of patients tolerated trihexyphenidyl well on a schedule of gradual dose increases, and almost all demonstrated improvements in dystonia or sialorrhea or both.

Quantification of functional near infrared spectroscopy to assess cortical reorganization in children with cerebral palsy.

Cerebral palsy (CP) is the most common motor disorder in children. Currently available neuroimaging techniques require complete body confinement and steadiness and thus are extremely difficult for pediatric patients. Here, we report the use and quantification of functional near infrared spectroscopy (fNIRS) to investigate the functional reorganization of the sensorimotor cortex in children with hemiparetic CP. Ten of sixteen children with congenital hemiparesis were measured during finger tapping tasks and compared with eight of sixteen age-matched healthy children, with an overall measurement success rate of 60%. Spatiotemporal analysis was introduced to quantify the motor activation and brain laterality. Such a quantitative approach reveals a consistent, contralateral motor activation in healthy children at 7 years of age or older. In sharp contrast, children with congenital hemiparesis exhibit all three of contralateral, bilateral and ipsilateral motor activations, depending on specific ages of the pediatric subjects. This study clearly demonstrates the feasibility of fNIRS to be utilized for investigating cortical reorganization in children with CP or other cortical disorders.

Identification of abnormal motor cortex activation patterns in children with cerebral palsy by functional near-infrared spectroscopy.

We demonstrate the utility of functional near-infrared spectroscopy (fNIRS) as a tool for physicians to study cortical plasticity in children with cerebral palsy (CP). Motor cortex activation patterns were studied in five healthy children and five children with CP (8.4+/-2.3 years old in both groups) performing a finger-tapping protocol. Spatial (distance from center and area difference) and temporal (duration and time-to-peak) image metrics are proposed as potential biomarkers for differentiating abnormal cortical activation in children with CP from healthy pediatric controls. In addition, a similarity image-analysis concept is presented that unveils areas that have similar activation patterns as that of the maximum activation area, but are not discernible by visual inspection of standard activation images. Metrics derived from the images presenting areas of similarity are shown to be sensitive identifiers of abnormal activation patterns in children with CP. Importantly, the proposed similarity concept and related metrics may be applicable to other studies for the identification of cortical activation patterns by fNIRS.

Reliability of the Tardieu Scale for assessing spasticity in children with cerebral palsy.

OBJECTIVE: To measure the Tardieu Scale's reliability in children with cerebral palsy (CP) when used by raters with and without experience in using the scale, before and after training. DESIGN: Single-center, intrarater and interrater reliability study. SETTING: Institutional ambulatory care. PARTICIPANTS: Referred children with CP in the pretraining phase (n=5), during training (n=3), and in the posttraining phase (n=15). INTERVENTIONS: The Tardieu Scale involves performing passive muscle stretch at 2 velocities, slow and fast. The rater derives 2 parameters; the Spasticity Angle X is the difference between the angles of arrest at slow speed and of catch-and-release or clonus at fast speed; the Spasticity Grade Y is an ordinal variable that grades the intensity (gain) of the muscle reaction to fast stretch. In phase 1, experienced raters without formalized training in the scale graded elbow, knee, and ankle plantar flexors bilaterally, without and with a goniometer. In phase 2, after training, the experienced and nonexperienced raters graded the same muscles unilaterally. MAIN OUTCOME MEASURES: Intrarater and interrater reliability of the Tardieu Scale. RESULTS: After training, nonexperienced raters had mean +/- SD intrarater and interrater agreement rates across all joints and parameters of 80%+/-14% and 74%+/-16%, respectively. For experienced raters, intrarater and interrater agreement rates before training were 77%+/-13% and 66%+/-15%, respectively, versus 90%+/-8% and 81%+/-13%, respectively, after training (P<.001 for both). Specific angle measurements at the knee were less reliable for the angles of catch measured at fast speed. Across all joints, agreement rates were similar using visual or goniometric measurements. CONCLUSIONS: Both parameters of the Tardieu Scale have excellent intrarater and interrater reliability when assessed at the elbow and ankle joints of children with CP, with no difference noted between visual and goniometric measurements. Angle measurements were less reliable at the knee joints. Training was associated with a highly significant improvement in reliability.

Management of children with holoprosencephaly.

Holoprosencephaly (HPE) is the most common malformation of the embryonic forebrain in humans. Although HPE occurs along a continuous spectrum, it has been categorized into four types from most severe to least severe: alobar, semilobar, lobar, and middle interhemispheric (MIH) variant. Facial malformations are often associated with HPE and usually correlate with the severity of brain malformation. With the most severely affected newborns, there is a high mortality rate in the first month of life, however, with milder forms of HPE, the majority survive beyond infancy. The Carter Centers for Brain Research in Holoprosencephaly and Related Malformations have enrolled 182 living children in a prospective research study. Based on previously published reports using this database, reports from other investigators, as well as our experience and personal observations, the range of developmental, neurological, and medical problems found in children with HPE is described in this article. Virtually all children with HPE have some developmental disability and the severity correlates with the severity of the brain malformation on neuroimaging. Common medical problems include hydrocephalus, seizures, motor impairment, oromotor dysfunction with risk of poor nutrition and aspiration, chronic lung disease, gastroesophageal reflux, constipation, hypothalamic dysfunction with disturbed sleep-wake cycles and temperature dysregulation, as well as endocrine dysfunction. Diabetes insipidus in particular is found in about 70% of children with classic HPE. Recommendations for management of these problems are given based on experiences of the authors and familiarity with the literature.

Parental perspectives on living with a child with HoPE.

This article describes the experiences and perceived needs of a small cohort of parents of children with holoprosencephaly (HPE). The factors that are important to the lives of children vary across families and stages of development. As children living with HPE grow and change, parents adapt their goals and expectations to reflect their child's now and future state. Relevant literature is integrated within the discussion to support recommendations for care.

Mutations in ZIC2 in human holoprosencephaly: description of a novel ZIC2 specific phenotype and comprehensive analysis of 157 individuals.

BACKGROUND: Holoprosencephaly (HPE), the most common malformation of the human forebrain, may be due to mutations in genes associated with non-syndromic HPE. Mutations in ZIC2, located on chromosome 13q32, are a common cause of non-syndromic, non-chromosomal HPE. OBJECTIVE: To characterise genetic and clinical findings in patients with ZIC2 mutations. METHODS: Through the National Institutes of Health and collaborating centres, DNA from approximately 1200 individuals with HPE spectrum disorders was analysed for sequence variations in ZIC2. Clinical details were examined and all other known cases of mutations in ZIC2 were included through a literature search. RESULTS: By direct sequencing of DNA samples of an unselected group of unrelated patients with HPE in our NIH laboratory, ZIC2 mutations were found in 8.4% (49/582) of probands. A total of 157 individuals from 119 unrelated kindreds are described, including 141 patients with intragenic sequence determined mutations in ZIC2. Only 39/157 patients have previously been clinically described. Unlike HPE due to mutations in other genes, most mutations occur de novo and the distribution of HPE types differs significantly from that of non-ZIC2 related HPE. Evidence is presented for the presence of a novel facial phenotype which includes bitemporal narrowing, upslanting palpebral fissures, a short nose with anteverted nares, a broad and well demarcated philtrum, and large ears. CONCLUSIONS: HPE due to ZIC2 mutations is distinct from that due to mutations in other genes. This may shed light on the mechanisms involved in formation of the forebrain and face and will help direct genetic counselling and diagnostic strategies.

Factor analysis of neuroanatomical and clinical characteristics of holoprosencephaly.

The objective of this study is to better understand the relationship between neuroradiologic and clinical characteristics in holoprosencephaly (HPE) using the multivariate analysis called factor analysis. HPE is a brain malformation characterized by incomplete cleavage of the cerebral hemispheres and deep gray structures. We performed evaluations on 89 children with HPE that included their history, developmental assessment, and physical examination. Ten clinical variables included in factor analysis were the grade of spasticity, dystonia, choreoathetosis, hypotonia, mobility, upper extremity/hand function, expressive language, feeding/swallowing difficulty, endocrinopathies, and temperature dysregulation. Five neuroimaging variables graded by pediatric neuroradiologists were the grade of HPE (from least to most severe: lobar, semilobar, and alobar) and the degree of non-separation of caudate, lentiform, thalamic, and hypothalamic nuclei. Factor analysis using principle component extraction and varimax rotation was utilized. Four significant factors were identified: (1) neuroimaging/developmental factor, (2) motor factor, (3) hypothalamic/oromotor factor, and (4) hypotonia factor. These four factors accounted for 65.2% of the variance. In this factor analysis of HPE patients, we were able to reduce the large number of clinical and radiological variables into four factors. These factors and the constructs underlying them provide structure to the data and provide key parameters for future studies involving neurodevelopmental outcomes in HPE.

Endocrine disorders associated with holoprosencephaly.

OBJECTIVE: To investigate the incidence of endocrinopathies in holoprosencephaly (HPE) and correlate the severity of the endocrinopathies with the neuroanatomic abnormalities. STUDY DESIGN: We reviewed the histories and medical records of 117 children with HPE for endocrinopathies and related treatments. Neuroimaging studies were graded for severity of HPE, hypothalamus non-separation, and pituitary abnormalities. RESULTS: Diabetes insipidus (DI) occurred in 70% of patients with classic HPE. The severity of the DI correlated with the grade of HPE and hypothalamic non-separation (p < 0.0001). Anterior pituitary dysfunctions were much less common. Hypothyroidism was identified in 11% of patients, hypocorticism in 7%, and growth hormone deficiency in 5%. Only one patient with middle interhemispheric variant of holoprosencephaly (MIH) had any of these disorders. CONCLUSIONS: Patients with HPE have a high incidence of DI that may be related to the failure of cleavage of hypothalamic nuclei. Anterior pituitary dysfunctions are much less common than DI.