Fetal macrocephaly: Pathophysiology, prenatal diagnosis and management

Macrocephaly means a large head and is defined as a head circumference (HC) above the 98th percentile or greater than +2SD above the mean for gestational age. Macrocephaly can be primary and due to increased brain tissue (megalocephaly), which in most cases is familial and benign or secondary. The latter may be due to various causes, including but not limited to communicating or non-communicating hydrocephalus, cerebral edema, focal and pericerebral increased fluid collections, thickened calvarium and brain tumors. Megalocephaly can be syndromic or non-syndromic. In the former, gyral and structural CNS anomalies are common. It is important to exercise caution when considering a diagnosis of megalocephaly due to limitations in the accuracy of HC measurement, lack of nomograms for specific populations, inconsistencies between prenatal and postnatal HC growth curves and progression over time. The degree of macrocephaly is important, with mild macrocephaly ≤2.5SD carrying a good prognosis, especially when one of the parents has macrocephaly and normal development. Cases in which the patient history and/or physical exam are positive or when parental HC are normal are more worrisome and warrant a neurosonogram, fetal MRI and genetic testing to better delineate the underlying etiology and provide appropriate counseling.

Subdural hemorrhage, macrocephaly, rash, and developmental delay in an infant: A pathogenic variant in NLRP3 causes CINCA/NOMID

Subdural hemorrhages (SDHs) in children are most often observed in abusive head trauma (AHT), a distinct form of traumatic brain injury, but they may occur in other conditions as well, typically with clear signs and symptoms of an alternative diagnosis. We present a case of an infant whose SDH initially raised the question of AHT, but multidisciplinary evaluation identified multiple abnormalities, including rash, macrocephaly, growth failure, and elevated inflammatory markers, which were all atypical for trauma. These, along with significant cerebral atrophy, ventriculomegaly, and an absence of other injuries, raised concerns for a genetic disorder, prompting genetic consultation. Clinical trio exome sequencing identified a de novo likely pathogenic variant in NLRP3, which is associated with chronic infantile neurological, cutaneous, and articular (CINCA) syndrome, also known as neonatal-onset multisystem inflammatory disease (NOMID). He was successfully treated with interleukin-1 blockade, highlighting the importance of prompt treatment in CINCA/NOMID patients. This case also illustrates how atraumatic cases of SDH can be readily distinguished from AHT with multidisciplinary collaboration and careful consideration of the clinical history and exam findings.

Childhood Neurologic Conditions: Neuroanatomic Abnormalities

Abnormal head shape and size often are apparent in infancy and typically are noted by caregivers or by clinicians on physical examination. Positional plagiocephaly consists of deformation of the skull not associated with an underlying skull fusion abnormality. This should be differentiated from craniosynostosis, which is the premature fusion of one or more skull sutures. For patients with craniosynostosis, early referral to a pediatric neurosurgeon or craniofacial specialist is important to prevent continued skull deformity and decrease the risk of increased intracranial pressure due to reduced skull adherence and obstruction of cerebrospinal fluid flow. Microcephaly is defined as a head circumference measuring 2 or more SDs below the mean for age and sex, and macrocephaly is defined as a head circumference measuring 2 or more SDs above the mean for age and sex. Etiologies of micro- and macrocephaly include perinatal factors, inherited head size, structural factors, and metabolic and genetic disorders. Brain imaging may be recommended. A rapid increase in head size should raise concerns about accumulation of cerebrospinal fluid and hydrocephalus, which may require emergent evaluation. A detailed history should be taken and a physical examination performed to identify any signs or symptoms of increased intracranial pressure.

Early diagnosis of Malan syndrome in an infant presenting with macrocephaly

We present an infant with persistent macrocephaly and developmental delay. There is a wide range of differential diagnoses for this presentation, including many rare genetic conditions. Here, a diagnosis of Malan syndrome was made-a rare overgrowth syndrome caused by haploinsufficiency of NFIX and features affecting the neurological and musculoskeletal systems. Improvements in genomic medicine technologies and clinical services have revolutionised the way clinicians diagnose rare diseases. We highlight the importance of early genetic testing, particularly if there are red flag features such as developmental delay, and the need for a coordinated strategy to improve the management of rare diseases like Malan syndrome.

[How I explore... macrocephaly]

Macrocephaly is a frequent reason for seeking advice in a pediatric neurology consultation. It is a non-specific neurological sign that can be isolated, be the sign of a serious acquired pathology or be part of a syndromic picture. Clinical history, physical examination and imaging are key elements of the diagnostic strategy. Signs of intracranial hypertension require an emergency work-up. Genetics, exome in particular, has enabled the characterization of various syndromes associating macrocephaly and neurodevelopmental delay. In this article, we propose an update of practices based on clinical signs.

Red flags for early recognition of adult patients with PTEN Hamartoma Tumour Syndrome

Patients with PTEN Hamartoma Tumour Syndrome (PHTS) are at increased risk of developing cancer. Many adult PHTS patients are not recognized as such and do not receive the cancer surveillance they need. Our aim was to define phenotypic characteristics that can easily be assessed and manifest by early adulthood, and hence could serve as red flags (i.e. alerting signals) for early recognition of adult patients at high risk of PHTS. Phenotypic characteristics including macrocephaly, multinodular goitre (MNG), and oral features were examined in 81 paediatric and 86 adult PHTS patients by one of two medical experts during yearly surveillance visits at our Dutch PHTS expert centre between 1997 and 2020. MNG was defined as signs of thyroid nodules and/or goitre. Oral features included gingival hypertrophy, high palate (adults only) and oral papillomas. Based on the characteristics' prevalence in different age groups, combinations of phenotypic characteristics were defined and evaluated on their potential to recognize individuals with PHTS. Macrocephaly was present in 100% of paediatric and 67% of adult patients. The prevalence of MNG was ∼50% in paediatric and gradually increased to >90% in adult patients. Similar percentages were observed for any of the oral features. Scoring two out of three of these characteristics yielded a sensitivity of 100% (95%CI 94-100%) in adults. The presence of the combination macrocephaly, MNG, or multiple oral features could serve as a red flag for general practitioners, medical specialists, and dentists to consider further assessment of the diagnosis PHTS in adults. In this way, recognition of adult PHTS patients might be improved and cancer surveillance can be offered timely.

Macrocephaly in the Primary Care Provider's Office

Macrocephaly is commonly encountered in the primary care provider's office. It is defined as an occipitofrontal circumference that is greater than 2 standard deviations above the mean for the child's given age. Macrocephaly is a nonspecific clinical finding that may be benign or require further evaluation. An algorithmic approach is useful for aiding in the clinical decision-making process to determine if further evaluation with neuroimaging is warranted. Abnormal findings may signify a harmful underlying cause, requiring referral to a genetic specialist or neurosurgeon.

Abnormal cranium development in children and adolescents affected by syndromes or diseases associated with neurodysfunction

Microcephaly and macrocephaly can be considered both cranial growth defects and clinical symptoms. There are two assessment criteria: one applied in dysmorphology and another conventionally used in clinical practice. The determination of which definition or under which paradigm the terminology should be applied can vary on a daily basis and from case to case as necessity dictates, as can defining the relationship between microcephaly or macrocephaly and syndromes or diseases associated with neurodysfunction. Thus, there is a need for standardization of the definition of microcephaly and macrocephaly. This study was designed to investigate associations between abnormal cranial development (head size) and diseases or syndromes linked to neurodysfunction based on essential data collected upon admission of patients to the Neurological Rehabilitation Ward for Children and Adolescents in Poland. The retrospective analysis involved 327 children and adolescents with medical conditions associated with neurodysfunction. Two assessment criteria were applied to identify subgroups of patients with microcephaly, normal head size, and macrocephaly: one system commonly used in clinical practice and another applied in dysmorphology. Based on the results, children and adolescents with syndromes or diseases associated with neurodysfunction present abnormal cranial development (head size), and microcephaly rarely co-occurs with neuromuscular disease. Macrocephaly frequently co-occurs with neural tube defects or neuromuscular diseases and rarely with cerebral palsy (p < 0.05); microcephaly frequently co-occurs with epilepsy and hypothyroidism (p < 0.001). Traditional classification facilitates the identification of a greater number of relationships and is therefore recommended for use in daily practice. There is a need to standardize the definition of microcephaly and macrocephaly and to include them in 'Human Phenotype Ontology' terms.

A novel HIST1HE pathogenic variant in a girl with macrocephaly and intellectual disability: a new case and review of literature

Pathogenic variants of HIST1H1Egene have recently been associated with a condition known as Rahman syndrome, characterized by overgrowth, intellectual disability and nonspecific dysmorphic features (high hairline, full cheeks, wide nasal bridge). Wide clinical variability is reported, especially regarding the level of neurodevelopment delay and intellectual disability. We report a 10-year-old girl with macrocephaly and global developmental delay, in whom a novel heterozygous variant in the HIST1H1Egene [c.392_395dup (p.Gly133fs)] was discovered, but involving the same C-terminal domain-protein domain reported previously. Comparing the clinical data of our patient with those previously described, a 'core phenotype' with macrocephaly, psychomotor delay/intellectual disability and mild facial dysmorphisms seems evident.

Mutations in the sonic hedgehog pathway cause macrocephaly-associated conditions due to crosstalk to the PI3K/AKT/mTOR pathway

The hedgehog (Hh) pathway is highly conserved and required for embryonic patterning and determination. Mutations in the Hh pathway are observed in sporadic tumors as well as under syndromic conditions. Common to these syndromes are the findings of polydactyly/syndactyly and brain overgrowth. The latter is also a finding most commonly observed in the cases of mutations in the PI3K/AKT/mTOR pathway. We have identified novel Hh pathway mutations and structural copy number variations in individuals with somatic overgrowth, macrocephaly, dysmorphic facial features, and developmental delay, which phenotypically closely resemble patients with phosphatase and tensin homolog (PTEN) mutations. We hypothesized that brain overgrowth and phenotypic overlap with syndromic overgrowth syndromes in these cases may be due to crosstalk between the Hh and PI3K/AKT/mTOR pathways. To test this, we modeled disease-associated variants by generating PTCH1 and Suppressor of Fused (SUFU) heterozygote cell lines using the CRISPR/Cas9 system. These cells demonstrate activation of PI3K signaling and increased phosphorylation of its downstream target p4EBP1 as well as a distinct cellular phenotype. To further investigate the mechanism underlying this crosstalk, we treated human neural stem cells with sonic hedgehog (SHH) ligand and performed transcriptional analysis of components of the mTOR pathway. These studies identified decreased expression of a set of mTOR negative regulators, leading to its activation. We conclude that there is a significant crosstalk between the SHH and PI3K/AKT/mTOR. We propose that this crosstalk is responsible for why mutations in PTCH1 and SUFU lead to macrocephaly phenotypes similar to those observed in PTEN hamartoma and other overgrowth syndromes associated with mutations in PI3K/AKT/mTOR pathway genes.

Recurrent mosaic MTOR c.5930C > T (p.Thr1977Ile) variant causing megalencephaly, asymmetric polymicrogyria, and cutaneous pigmentary mosaicism: Case report and review of the literature

Genetic alterations leading to overactivation of mammalian target of rapamycin (mTOR) signaling result in brain overgrowth syndromes such as focal cortical dysplasia (FCD) and megalencephaly. Megalencephaly with cutis tri-color of the Blaschko-linear type pigmentary mosaicism and intellectual disability is a rare neurodevelopmental disorder attributed to the recurrent mosaic c.5930C > T (p.Thr1977Ile) MTOR variant. This variant was previously reported at low to intermediate levels of mosaicism in the peripheral blood of three unrelated individuals with consistent clinical findings. We report a fourth case of a 3-year-old female presenting with megalencephaly, obstructive hydrocephalus due to cerebral aqueductal stenosis, asymmetric polymicrogyria, dysgenesis of the corpus callosum, hypotonia, developmental delay, and cutaneous pigmentary mosaicism. Oligonucleotide and SNP chromosomal microarray (CMA), karyotype, and trio whole exome sequencing (WES) in the peripheral blood, as well as a targeted gene variant panel from fibroblasts derived from hyperpigmented and non-hyperpigmented skin did not detect any abnormalities in MTOR or other genes associated with brain overgrowth syndromes. Unlike the previously reported cases, the de novo c.5930C > T (p.Thr1977Ile) MTOR variant was detected at 32% mosaicism in our patient only after WES was performed on fibroblast-derived DNA from the hyperpigmented skin. This case demonstrates the tissue variability in mosaic expression of the recurrent p.Thr1977Ile MTOR variant, emphasizes the need for skin biopsies in the genetic evaluation of patients with skin pigmentary mosaicism, and expands the clinical phenotype associated with this pathogenic MTOR variant.

[Macrocephaly in childhood]

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.

Hypoinsulinaemic, hypoketotic hypoglycaemia due to mosaic genetic activation of PI3-kinase

OBJECTIVE

Genetic activation of the insulin signal-transducing kinase AKT2 causes syndromic hypoketotic hypoglycaemia without elevated insulin. Mosaic activating mutations in class 1A phospatidylinositol-3-kinase (PI3K), upstream from AKT2 in insulin signalling, are known to cause segmental overgrowth, but the metabolic consequences have not been systematically reported. We assess the metabolic phenotype of 22 patients with mosaic activating mutations affecting PI3K, thereby providing new insight into the metabolic function of this complex node in insulin signal transduction.

METHODS

Three patients with megalencephaly, diffuse asymmetric overgrowth, hypoketotic, hypoinsulinaemic hypoglycaemia and no AKT2 mutation underwent further genetic, clinical and metabolic investigation. Signalling in dermal fibroblasts from one patient and efficacy of the mTOR inhibitor Sirolimus on pathway activation were examined. Finally, the metabolic profile of a cohort of 19 further patients with mosaic activating mutations in PI3K was assessed.

RESULTS

In the first three patients, mosaic mutations in PIK3CA (p.Gly118Asp or p.Glu726Lys) or PIK3R2 (p.Gly373Arg) were found. In different tissue samples available from one patient, the PIK3CA p.Glu726Lys mutation was present at burdens from 24% to 42%, with the highest level in the liver. Dermal fibroblasts showed increased basal AKT phosphorylation which was potently suppressed by Sirolimus. Nineteen further patients with mosaic mutations in PIK3CA had neither clinical nor biochemical evidence of hypoglycaemia.

CONCLUSIONS

Mosaic mutations activating class 1A PI3K cause severe non-ketotic hypoglycaemia in a subset of patients, with the metabolic phenotype presumably related to the extent of mosaicism within the liver. mTOR or PI3K inhibitors offer the prospect for future therapy.

A clinical review on megalencephaly: A large brain as a possible sign of cerebral impairment

Megalencephaly and macrocephaly present with a head circumference measurement 2 standard deviations above the age-related mean. However, even if pathologic events resulting in both megalencephaly and macrocephaly may coexist, a distinction between these two entities is appropriate, as they represent clinical expression of different disorders with a different approach in clinical work-up, overall prognosis, and treatment. Megalencephaly defines an increased growth of cerebral structures related to dysfunctional anomalies during the various steps of brain development in the neuronal proliferation and/or migration phases or as a consequence of postnatal abnormal events. The disorders associated with megalencephaly are classically defined into 3 groups: idiopathic or benign, metabolic, and anatomic. In this article, we seek to underline the clinical aspect of megalencephaly, emphasizing the main disorders that manifest with this anomaly in an attempt to properly categorize these disorders within the megalencephaly group.

Autism spectrum disorder in sub-saharan africa: A comprehensive scoping review

Autism spectrum disorder (ASD) is recognized as a global public health concern, yet almost everything we know about ASD comes from high-income countries. Here we performed a scoping review of all research on ASD ever published in sub-Saharan Africa (SSA) in order to identify ASD knowledge gaps in this part of the world. Fifty-three publications met inclusion criteria. Themes included the phenotype, genetics and risk factors for ASD in SSA, screening and diagnosis, professional knowledge, interventions for ASD, parental perceptions, and social-cognitive neuroscience. No epidemiological, early intervention, school-based or adult studies were identified. For each identified theme, we aimed to summarize results and make recommendations to fill the knowledge gaps. The quality of study methodologies was generally not high. Few studies used standardized diagnostic instruments, and intervention studies were typically small-scale. Overall, findings suggest a substantial need for large-scale clinical, training, and research programmes to improve the lives of people who live with ASD in SSA. However, SSA also has the potential to make unique and globally-significant contributions to the etiology and treatments of ASD through implementation, interventional, and comparative genomic science. Autism Res 2017, 10: 723-749. © 2017 International Society for Autism Research, Wiley Periodicals, Inc.

[Neuhauser syndrome: the facial dysmorphic phenotype]

Neuhauser syndrome is an extremely rare genetic disease, most cases are sporadic by spontaneous mutation, but there are cases of autosomal recessive genetic transmission; the specific cause is unknown and has no diagnostic test. The disease is clinically characterized by primary megalocornea, congenital hypotonia, mental retardation of varying degree and delayed psychomotor development. The diagnosis in childhood is usually performed by oculo-neurological criteria. The patients have a peculiar face by specific craniofacial anomalies: round face, wide prominent forehead, hypertelorism, broad nasal bridge, bulbous nose, wide philtrum nasolabial wide, thin elongated mouth, big and protuded ear "cup", jaw undersized (micrognathia) and abnormal posterior positioning of the mandible (retrognathia).The use of facial dysmorphism helps to delineate the phenotype and achieve the punctuation required for the diagnosis, allowing early management and prevention of complications.

Intellectual disability, coarse face, relative macrocephaly, and cerebellar hypotrophy in two sisters

We report on two Portuguese sisters with a very similar phenotype characterized by severe intellectual disability, absent speech, relative macrocephaly, coarse face, cerebellar hypotrophy, and severe ataxia. Additional common features include increased thickness of the cranial vault, delayed dental eruption, talipes equino-varus, clinodactyly, and camptodactyly of the fifth finger. The older sister has retinal dystrophy and the younger sister has short stature. Their parents are consanguineous. We suggest this condition constitutes a previously unreported autosomal recessive entity.

Neurodevelopmental delays and macrocephaly in 17p13.1 microduplication syndrome

Microduplication of chromosome 17p13.1 is a rarely reported chromosome abnormality associated with neurodevelopmental delays. We describe two unrelated patients with overlapping microduplications of chromosome 17p13.1. The first patient is a 2-year-old male who presented with neurodevelopmental delays and macrocephaly. He was found to have a de novo 788 kb copy gain of 17p13.2p13.1 and a de novo 134 kb copy gain of 17p13.1. These duplications include multiple candidate genes, including EFNB3, NLGN2, DLG4, GABARAP, and DULLARD, which may be responsible for neurodevelopmental delays in affected individuals. The second patient is a 29-year-old female with mild intellectual disability and relative macrocephaly. She was found to have a 62.5 kb copy gain of chromosome 17p13.1 that includes the DLG4, GABARAP, and DULLARD genes. The DLG4, GABARAP, and DULLARD genes included in the microduplications of both our patients appear to be candidate genes for neurodevelopmental delays and macrocephaly in individuals with 17p13.1 microduplication syndrome.

[Cowden syndrome diagnosed in patients with macrocephaly]

Cowden syndrome is a rare autosomal dominant syndrome with a predisposition to cancer. We present a case of Cowden syndrome in a mother and her son, who were diagnosed with palmoplantar hyperkeratosis, macrocephaly and goitre. Early diagnosis is a challenge as the patients present with a variety of symptoms, but it is important because of the risk of cancer.

[Primary amenorrhoea and macrocephaly]

BACKGROUND

Primary amenorrhoea has a broad differential diagnosis. When hypogonadotropic hypogonadism is present, possible intracranial abnormalities should always be suspected.

CASE DESCRIPTION

We present the case of a 16-year-old girl with primary amenorrhoea. Laboratory investigations showed hypogonadotropic hypogonadism. MRI of the brain revealed a secondary hydrocephalus, caused by a retrocerebellar arachnoid cyst. The increased pressure from the third ventricle on the hypothalamus caused a functional gonadotropin-releasing hormone (GnRH) deficiency, leading to primary amenorrhoea. Menarche occurred after neurosurgical intervention and the patient developed a regular cycle. In hindsight, the hydrocephalus could have been discovered earlier, because of the development of macrocephaly during the first years of life.

CONCLUSION

This case illustrates the importance of head circumference measurements, even after the first year of life, and the importance of further investigation if an abnormal growth pattern is revealed. Imaging investigations of the brain should always be carried out in cases of primary amenorrhoea accompanied by low gonadotropin levels (central hypogonadism).

Prevalence of subdural collections in children with macrocrania

BACKGROUND AND PURPOSE

The relationship between enlarged subarachnoid spaces and subdural collections is poorly understood and creates challenges for clinicians investigating the etiology of subdural collections. The purpose of this study was to determine the prevalence of subdural collections on cross sectional imaging in children with macrocephaly correlating with subarachnoid space enlargement.

MATERIALS AND METHODS

The radiology information system of a large pediatric medical center was reviewed for "macrocrania" and "macrocephaly" on reports of cranial MRI/CT examinations in children <24 months of age, over a 24-month period. Head circumference was obtained from the clinical record. Studies were reviewed blindly for subdural collection presence and subarachnoid space size. Children with prior cranial surgery, parenchymal abnormalities, hydrocephalus, or conditions predisposing to parenchymal volume loss were excluded. Chart review was performed on those with subdural collections.

RESULTS

Imaging from 177 children with enlarged head circumference was reviewed. Nine were excluded, for a final cohort of 168 subjects (108 with enlarged subarachnoid space). Subdural collections were identified in 6 (3.6%), all with enlarged subarachnoid space (6/108, 5.6%). In 4, subdural collections were small, homogeneous, and nonhemorrhagic. In 2, the collections were complex (septations or hemorrhage). Two children were reported as victims of child abuse (both with complex collections). No definitive etiology was established in the other cases.

CONCLUSIONS

The prevalence of subdural collections in imaged children with macrocrania was 3.6%, all occurring in children with enlarged subarachnoid space. Our results suggest that enlarged subarachnoid space can be associated with some subdural collections in this cohort. Despite this, we believe that unexpected subdural collections in children should receive close clinical evaluation for underlying causes, including abusive head trauma.

47,XYY syndrome: clinical phenotype and timing of ascertainment

OBJECTIVE

To describe auxologic, physical, and behavioral features in a large cohort of males with 47,XYY (XYY), ages newborn to young adult.

STUDY DESIGN

This is a cross-sectional descriptive study of male subjects with XYY who were evaluated at 1 of 2 specialized academic sites. Subjects underwent a history, physical examination, laboratory testing, and cognitive/behavioral evaluation.

RESULTS

In 90 males with XYY (mean age 9.6 ± 5.3 years [range 0.5-36.5]), mean height SD was above average (1.0 ± 1.2 SD). Macrocephaly (head circumference >2 SD) was noted in 28/84 (33%), hypotonia in 57/90 (63%), clinodactyly in 47/90 (52%), and hypertelorism in 53/90 (59%). There was testicular enlargement for age (>2 SD) in 41/82 (50%), but no increase in genital anomalies. No physical phenotypic differences were seen in boys diagnosed prenatally vs postnatally. Testosterone, luteinizing hormone, and follicle stimulating hormone levels were in the normal range in most boys. There was an increased incidence of asthma, seizures, tremor, and autistic spectrum disorder (ASD) compared with the general population rates. Prenatally diagnosed boys scored significantly better on cognitive testing and were less likely to be diagnosed with ASD (P < .01).

CONCLUSIONS

The XYY phenotype commonly includes tall stature, macrocephaly, macroorchidism, hypotonia, hypertelorism, and tremor. Physical phenotypic features were similar in boys diagnosed prenatally vs postnatally. Prenatal diagnosis was associated with higher cognitive function and less likelihood of an ASD diagnosis.

Head circumferences in twins with and without Autism Spectrum Disorders

To determine the genetic relationship between head circumference (HC) and Autism Spectrum Disorders (ASDs). Twin pairs with at least one twin with an ASD were assessed. HCs in affected and unaffected individuals were compared, as were HC correlations in monozygotic and dizygotic pairs. 404 subjects, ages 4-18, were included. 20 % of males and 27 % of females with an ASD had macrocephaly. Unaffected co-twins showed similar rates (16 % of males and 22 % of females). Statistical analysis revealed no significant difference in HCs between affected and unaffected twins. Twins with ASDs and unaffected co-twins have similar HCs and increased rates of macrocephaly. Correlations demonstrated partial inheritance of HCs. Thus, macrocephaly may represent an endophenotype in ASDs.

Macrocephaly with multiple epiphyseal dysplasia: a second example of Al Gazali-Bakalinova syndrome?

Four individuals from one consanguineous family affected with macrocephaly, multiple epiphyseal dysplasia and distinctive facies were presented by Al Gazali and Bakalinova in 1998 (1) as a distinct clinical entity. To the best of our knowledge, no other similarly affected family has been presented in the literature. Here, we present an affected macrocephalic male, from a consanguineous family, with facial anomalies, cranial MRI findings and multiple epiphyseal dysplasia findings. We believe this is the second family with a similar clinical spectrum and the same inheritance pattern as those of the family presented by Al Gazali and Bakalinova. Pectus carinatum, hip dislocation and a history of prenatal polyhydramnios have been noted as additional findings in our patient.

Can syndromic macrocephaly be diagnosed in utero?

OBJECTIVES

To compare the outcomes of fetuses with apparently isolated macrocephaly and those with associated findings, and to compare prenatal findings with postnatal diagnoses in children with syndromic macrocephaly.

METHODS

We reviewed the files of all patients referred for suspected fetal macrocephaly, during a 10-year period from 2000, to a large prenatal diagnosis unit with expertise in fetal neurology counseling. Macrocephaly was defined as head circumference (HC) > 2 SDs of the norm. Patients with confirmed HC > 2 SD were identified and contacted, and their development was evaluated.

RESULTS

Adequate data for analysis were available for 98 patients, in 82 of whom the fetal macrocephaly was considered isolated (Group A), and in 16 of whom associated fetal anomalies were identified (Group B). Macrocephaly was diagnosed earlier in Group B patients (28.4 vs. 32.3 weeks, P = 0.069), and the HC in Group B patients was larger (Z-score 2.95 vs. 2.3, P < 0.001). From Group A there were 81 liveborn; one of whom was diagnosed as having infantile autism. From Group B, there were nine liveborn. The associated central nervous system findings, as demonstrated by ultrasound and magnetic resonance imaging, included mild ventriculomegaly, malformations of cortical development, callosal abnormalities, overdeveloped sulcation, large cavum septi pellucidi, large subarachnoid spaces, mega cisterna magna, periventricular pseudocyst, open operculum and vermian dysgenesis. Syndromic diagnosis was made in utero in five fetuses and after birth in three. In eight patients, associated malformations were confirmed after birth but a specific diagnosis was not reached.

CONCLUSIONS

When fetal macrocephaly is associated with other brain or systemic anomalies, syndromic macrocephaly can be diagnosed in utero. Fetuses with syndromic macrocephaly have a significantly larger HC, usually > 2.5 SD above the mean. Isolated macrocephaly, particularly when the HC is < 2.5 SD above the norm, may be clinically benign.