Environmental Enrichment Rescues Social Behavioral Deficits and Synaptic Abnormalities in Pten Haploinsufficient Mice.

Pten germline haploinsufficient (Pten+/-) mice, which model macrocephaly/autism syndrome, show social and repetitive behavior deficits, early brain overgrowth, and cortical-subcortical hyperconnectivity. Previous work indicated that altered neuronal connectivity may be a substrate for behavioral deficits. We hypothesized that exposing Pten+/- mice to environmental enrichment after brain overgrowth has occurred may facilitate adaptation to abnormal "hard-wired" connectivity through enhancing synaptic plasticity. Thus, we reared Pten+/- mice and their wild-type littermates from weaning under either standard (4-5 mice per standard-sized cage, containing only bedding and nestlet) or enriched (9-10 mice per large-sized cage, containing objects for exploration and a running wheel, plus bedding and nestlet) conditions. Adult mice were tested on social and non-social assays in which Pten+/- mice display deficits. Environmental enrichment rescued sex-specific deficits in social behavior in Pten+/- mice and partially rescued increased repetitive behavior in Pten+/- males. We found that Pten+/- mice show increased excitatory and decreased inhibitory pre-synaptic proteins; this phenotype was also rescued by environmental enrichment. Together, our results indicate that environmental enrichment can rescue social behavioral deficits in Pten+/- mice, possibly through normalizing the excitatory synaptic protein abundance.

Inclusion of hemimegalencephaly into the phenotypic spectrum of NPRL3 pathogenic variants in familial focal epilepsy with variable foci.

Despite tremendous progress through next generation sequencing technologies, familial focal epilepsies are insufficiently understood. We sought to identify the genetic basis in multiplex Palestinian families with familial focal epilepsy with variable foci (FFEVF). Family I with 10 affected individuals and Family II with five affected individuals underwent detailed phenotyping over three generations. The phenotypic spectrum of the two families varied from nonlesional focal epilepsy including nocturnal frontal lobe epilepsy to severe structural epilepsy due to hemimegalencephaly. Whole-exome sequencing and single nucleotide polymorphism array analysis revealed pathogenic variants in NPRL3 in each family, a partial ~38-kb deletion encompassing eight exons (exons 8-15) and the 3'-untranslated region of the NPRL3 gene in Family I, and a de novo nonsense variant c.1063C>T, p.Gln355* in Family II. Furthermore, we identified a truncating variant in the PDCD10 gene in addition to the NPRL3 variant in a patient with focal epilepsy from Family I. The individual also had developmental delay and multiple cerebral cavernomas, possibly demonstrating a digenic contribution to the individual's phenotype. Our results implicate the association of NPRL3 with hemimegalencephaly, expanding the phenotypic spectrum of NPRL3 in FFEVF and underlining that partial deletions are part of the genotypic spectrum of NPRL3 variants.

Reverse Distraction for Treatment of Hydrocephalic Macrocephaly in Late Childhood.

Macrocephaly diminishes quality of life for children whose head size inhibits independent mobility and appropriate interaction with caregivers. Cranial reduction is a method of addressing these issues, historically with a high morbidity due most commonly to bleeding and shunt complications. The authors present a 9-year-old girl with holoprosencephaly and severe macrocephaly from progressive hydrocephalus who underwent cranial reduction via reverse distraction osteogenesis, a method to slowly reduce the skull volume. The patient underwent circumferential occipital temporoparietal frontal craniotomy with placement of 4 cranial distractors, followed approximately 1 month later by removal of the distractors and cranioplasty with resorbable fixation devices. The patient demonstrated significant postoperative improvement in head control and interaction in school activities. This is the oldest patient with macrocephaly treated with reverse distraction in the literature to date. The slow contraction of the cranial vault with limited bony surgery at the time of initial reduction provides an additional safety margin, and should be considered in older children presenting with profound macrocephaly.

[Macrocephaly in childhood]. / Macrocefalia en la infancia.

In a wide spectrum of cases in childhood, macrocephaly does not carry a neurological risk, although a range of possibilities will have an impact on both the evolutionary and cognitive aspects of children. The previous happens in pathologies with progressive components, such as tumors or hydrocephalus, and in those cases in which the factor of the growth of the cephalic perimeter is given by structural components of the nervous system as it happens in megalocephaly. As in all other medical acts, the careful taking of the anamnesis, the appropriate neurological examination and the valuations of the neurodevelopment items can give a thorough orientation about the etiology and importance of the problem. The help of diagnostic aids as well as images will provide the other data to define the diagnosis and propose a treatment.

Clinical, radiological, and auxological characteristics of patients with cleidocranial dysplasia followed in a pediatric referral hospital in Argentina. / Características clínicas, radiológicas y auxológicas de pacientes con displasia cleidocraneal seguidos en un hospital pediátrico de referencia en Argentina.

Cleidocranial dysplasia is an autosomal dominant skeletal dysplasia caused by mutations in the RUNX2 gene; its prevalence has been estimated at 1/1 000 000 newborn infants. This study presents 37 patients (22 girls) assessed between 1992 and 2016 at the Skeletal Dysplasias Multidisciplinary Clinics of Hospital Garrahan, Argentina. FINDINGS: 35% of positive family history; median age at the time of diagnosis: 2.61 years old; positive radiological findings in the skull and pubis: 95%; in the clavicles: 100%. Dental and hearing complications were common. Auxology: boys had a median height of -1.81 SD (-3.26 to 0.2) and girls had a median height of -1.36 SD (-4.28 to 1.36). Five out of 13 patients were short for parental height. Adult height (median): 162.8 cm in boys and 149.2 cm in girls. No evident alterations were observed in the sitting height/height ratio. One patient had true macrocephaly; 12 (32%), relative macrocephaly. Intrafamily variability was described in terms of height.

La displasia cleidocraneal es una displasia esquelética autosómica dominante causada por mutaciones en el gen RUNX2, con una prevalencia estimada de 1/1 000 000 de recién nacidos. Se presentan 37 pacientes (22 mujeres) evaluados entre 1992 y 2016 en las clínicas de displasias esqueléticas, Hospital Garrahan, Argentina. Hallazgos: 35% de antecedentes familiares positivos; edad mediana al momento del diagnóstico: 2,61 años; características radiológicas positivas en el cráneo y el pubis: 95%; en las clavículas: 100%. Las complicaciones dentales y auditivas fueron comunes. Auxología: mediana de estatura de -1,81 (-3,26-0,2) DE en los varones, -1,36 (-4,28-1,36) DE en las mujeres. Cinco de trece pacientes fueron bajos para la estatura parental. Estatura adulta (mediana): 162,8 cm y 149,2 cm en los varones y las mujeres. No fueron evidentes alteraciones en la proporción estatura sentada/estatura. Un paciente presentó macrocefalia real; 12 (32%), macrocefalia relativa. Se describe variabilidad intrafamiliar de estatura.

Megalencephalic leucoencephalopathy with subcortical cysts: subcortical diffuse leucoencephalopathy associated with white matter cystic degeneration.

Megalencephalic leucoencephalopathy with subcortical cysts (MLC) is a diffuse subcortical leucoencephalopathy with cystic white matter degeneration. Patients with MLC present with macrocephaly at the first year of life, and neurological abnormalities such as motor deterioration, ataxia, spasticity and cognitive defects progress later. MLC is caused by mutations in the gene MLC1, which encodes a novel protein, MLC1. There is no specific treatment for MLC. Management is based on physiotherapy procedures, psychomotor stimulation and treatment of seizures. We report a case of a 1-year-old boy with a normal birth and developmental history, presenting with progressive increase of head size; on further evaluation with CT and MRI of the brain, the child was diagnosed as MLC.

[Patients with basal cell naevus syndrome should be offered an early multidisciplinary follow-up and treatment]. / Patienter med basalcellenævussyndrom bør tilbydes tidlig interdisciplinær opfølgning og behandling.

Basal cell naevus syndrome (Gorlin-Goltz syndrome) is a rare, autosomal dominantly inherited condition with a wide range of developmental and multiple organ-related anomalies. Cardinal features include multiple basal cell carcinomas, jaw cysts, palmoplantar pits and calcification of the falx cerebri. Other important clinical features are skeletal abnormalities and facial dysmorphism including macrocephaly. Germ-line mutations are found in PTCH1. Management of the syndrome requires a multidisciplinary approach, and in this article management guidelines are reviewed and discussed.

Clinical presentation of PTEN mutations in childhood in the absence of family history of Cowden syndrome.

BACKGROUND: PTEN gene (MIM 601628) is a tumor suppressor gene implicated in PTEN hamartoma tumor syndromes (PHTS) including Cowden syndrome, Bannayan-Riley-Ruvalcaba syndrome, and Proteus-like syndrome. Bannayan-Riley-Ruvalcaba syndrome is considered as the pediatric form of PHTS. More recently, children presenting autism spectrum disorders with macrocephaly (ASD-M) have been reported. METHODS: We report clinical data from seven patients diagnosed in childhood with a PTEN germline mutation, excluding cases of familial Cowden syndrome. RESULTS: This study underlines the variability of phenotype associated with PTEN mutations diagnosed at pediatric age. Most of the patients did not fulfill usual criteria of Bannayan-Riley-Ruvalcaba syndrome or ASD-M. CONCLUSION: PTEN testing should be considered in any child presenting with severe macrocephaly (>+4SD) and another feature of PHTS.

Germline activating AKT3 mutation associated with megalencephaly, polymicrogyria, epilepsy and hypoglycemia.

Activating germ-line and somatic mutations in AKT3 (OMIM 611223) are associated with megalencephaly-polymicrogyria-polydactyly-hydrocephalus syndrome (MPPH; OMIM # 615937) and megalencephaly-capillary malformation (MCAP; OMIM # 602501). Here we report an individual with megalencephaly, polymicrogyria, refractory epilepsy, hypoglycemia and a germline AKT3 mutation. At birth, head circumference was 43 cm (5 standard deviations above the mean). No organomegaly was present, but there was generalized hypotonia, joint and skin laxity, developmental delay and failure to thrive. At 6 months of age the patient developed infantile spasms that were resistant to antiepileptic polytherapy. Recurrent hypoglycemia was noted during treatment with adrenocorticotropic hormone but stabilized upon introduction of continuous, enriched feeding. The infantile spasms responded to the introduction of a ketogenic diet, but the hypoglycemia recurred until the diet was adjusted for increased resting energy expenditure. A novel, de novo AKT3 missense variant (exon 5; c.548T>A, p.(V183D)) was identified and shown to activate AKT3 by in vitro functional testing. We hypothesize that the sustained hypoglycemia in this patient is caused by increased glucose utilization due to activation of AKT3 signaling. This might explain the efficacy of the ketogenic diet in this individual.

Enfrentamiento de macrocefalia en niños / Management of macrocephaly in children

En la mayoría de los niños con macrocefalia no se encuentra una causagrave, sin embargo, deben considerarse en el diagnóstico etiológico cuadros tratables y/o progresivos como una hidrocefalia. Un análisis cuidadoso y ordenado de los datos obtenidos en anamnesis y examen físico/neurológico, y una adecuada valoración del desarrollo psicomotor permitirán definir las probables causas de la macrocefalia y exámenes complementarios, evitando realizar procedimientos innecesarios.

Although most children with macrocephaly do not have a serious cause, treatable or progressive disorders as hydrocephalus must be considered in the diagnostic workup. A careful and orderly analysis of data obtained from anamnesis and physical / neurological examination, and a proper assessment of psychomotor development will allow the definition of likely causes of macrocephaly and examinations to accomplish, avoiding performing unnecessary procedures.

Resistance to thyroid hormone caused by a mutation in thyroid hormone receptor (TR)α1 and TRα2: clinical, biochemical, and genetic analyses of three related patients.

BACKGROUND: The thyroid hormone receptor α gene (THRA) transcript is alternatively spliced to generate either thyroid hormone receptor (TR)α1 or a non-hormone-binding variant protein, TRα2, the function of which is unknown. Here, we describe the first patients identified with a mutation in THRA that affects both TRα1 and TRα2, and compare them with patients who have resistance to thyroid hormone owing to a mutation affecting only TRα1, to delineate the relative roles of TRα1 and TRα2. METHODS: We did clinical, biochemical, and genetic analyses of an index case and her two sons. We assessed physical and radiological features, thyroid function, physiological and biochemical markers of thyroid hormone action, and THRA sequence. FINDINGS: The patients presented in childhood with growth failure, developmental delay, and constipation, which improved after treatment with thyroxine, despite normal concentrations of circulating thyroid hormones. They had similar clinical (macrocephaly, broad faces, skin tags, motor dyspraxia, slow speech), biochemical (subnormal ratio of free thyroxine:free tri-iodothyronine [T3], low concentration of total reverse T3, high concentration of creatine kinase, mild anaemia), and radiological (thickened calvarium) features to patients with TRα1-mediated resistance to thyroid hormone, although our patients had a heterozygous mis-sense mutation (Ala263Val) in both TRα1 and TRα2 proteins. The Ala263Val mutant TRα1 inhibited the transcriptional function of normal receptor in a dominant-negative fashion. By contrast, function of Ala263Val mutant TRα2 matched its normal counterpart. In vitro, high concentrations of T3 restored transcriptional activity of Ala263Val mutant TRα1, and reversed the dominant-negative inhibition of its normal counterpart. High concentrations of T3 restored expression of thyroid hormone-responsive target genes in patient-derived blood cells. INTERPRETATION: TRα1 seems to be the principal functional product of the THRA gene. Thyroxine treatment alleviates hormone resistance in patients with mutations affecting this gene, possibly ameliorating the phenotype. These findings will help the diagnosis and treatment of other patients with resistance to thyroid hormone resulting from mutations in THRA. FUNDING: Wellcome Trust, NIHR Cambridge Biomedical Research Centre, Marie Curie Actions, Foundation for Development of Internal Medicine in Europe.

Man with macrocephaly, learning disability and multiple basal cell carcinomas.

Gorlin syndrome is a rare genetic condition in which patients may develop medulloblastomas, jaw cysts and basal cell carcinomas and show congenital skeletal malformations. If left undiagnosed, Gorlin syndrome can have a number of negative consequences. Early diagnosis and good follow-up is important for all patients with rare disorders. We wish to make doctors and dentists aware of Gorlin syndrome so that, whenever the syndrome is suspected or a patient has been diagnosed, the patient is referred for assessment, treatment and follow-up by specialists who know the disorder well. Dermatology departments at university hospitals and departments of medical genetics have a key role to play in assessment and follow-up. A national support group for Gorlin syndrome has been established, consisting of a dermatologist, oncologist, geneticist, paediatrician, specialist dentist, ophthalmologist, orthopaedic surgeon, plastic surgeon, oral and maxillofacial surgeon and counsellors. Patients, relatives and health professionals can contact the Centre for Rare Disorders directly for information about Gorlin syndrome, or to be put in touch with members of the group.

Atypical focal cortical dysplasia in a patient with Cowden syndrome.

A macrocephalic girl presented with generalised epilepsy due to focal cortical dysplasia. She later developed multiple hamartomatous lesions and was diagnosed to have Cowden syndrome. The diagnosis was confirmed by identification of a novel frameshift mutation in the PTEN gene of the patient.

Acting on macrocephaly in the neonatal period: an illustrative case of congenital teratoma.

An 11-week-old baby was brought to the paediatric emergency department by his mother with a 2-day history of inconsolable crying. On examination, clinical features of macrocephaly, separated sutures and 'sunsetting' of the eyes were noted. Abnormal head circumference measurements had been obtained on several occasions since birth, but were not acted on contrary to local guidance. During the emergency admission, an urgent CT scan revealed a large posterior fossa tumour consistent with a teratoma causing severe obstructive hydrocephalus. Following referral to a neurosurgical centre, emergency ventricular drainage and debulking surgery were performed, unfortunately with no option for cure. Distress to mother and baby could have been reduced with a more timely diagnosis.