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At least 19 recordsLinked to original sources
PubMed1997

Malnutrition and microcephaly in Australian aboriginal children.

OBJECTIVE: To examine the association between malnutrition and microcephaly in the first two years of life. DESIGN: Cross-sectional study. SETTING AND PARTICIPANTS: Royal Darwin Hospital (a tertiary referral centre); 157 of 165 previously studied Aboriginal children aged under two years who were admitted with diarrhoea between May 1990 and April 1991. Birth weight, birth length, birth head circumference, admission head circumference and admission nutritional status were examined. Nutritional status was categorised according to World Health Organization (WHO) criteria for wasting (thinness) and stunting (shortness). Microcephaly on admission was defined as a head circumference less than the second percentile on Australian reference charts. Small-for-gestational-age (SGA) and birth microcephaly were defined as being less than the tenth percentile for an Australian hospitalised population, corrected for gestational age at confinement. Low birth weight (LBW) was defined as less than 2500 g. MAIN OUTCOME MEASURE: Microcephaly on admission. RESULTS: Of the 157 children, 76 (48%) were wasted, 36 (23%) stunted and 37 (24%) microcephalic on admission. A total of 26 (17%) children had been of LBW, 17 (11%) SGA and 21 (13%) microcephalic at birth. On univariate analysis, microcephaly on admission was associated with wasting (crude odds ratio [OR], 3.91; 95% confidence interval [CI], 1.6-9.7; P < 0.005), but not stunting. There were no significant associations between microcephaly on admission and LBW, being SGA, microcephaly at birth, age or sex. With multivariate analysis, birth head circumference was significantly associated with microcephaly on admission (adjusted OR, 3.62; 95% CI, 1.28-10.23; P < 0.05), as was wasting (adjusted OR, 4.38; 95% CI, 1.88-10.20; P < 0.001). CONCLUSIONS: Wasting was significantly associated with microcephaly, independent of intrauterine growth retardation (as measured by being SGA) and LBW. As malnutrition in critical periods of both intra- and extrauterine development may have irreversible effects on intellectual potential and behaviour, the emphasis on improved nutrition must begin during pregnancy, and should continue in infancy and early childhood.

Analysis of Variance↗
PubMed1993

Blepharophimosis sequence (BPES) and microcephaly in a girl with del(3) (q22.2q23): a putative gene responsible for microcephaly close to the BPES gene?

We report on a girl with the blepharophimosis sequence (BPES), microcephaly of postnatal onset, mild developmental retardation, and a deletion: 46,XX,del(3) (q22.2q23) de novo. A gene for BPES is suspected to be located at 3q23. Almost all cases with interstitial deletions containing 3q23 have not only BPES but also microcephaly and developmental retardation, while those without deletions, including those with apparently balanced translocations, only have BPES. Thus, a putative gene responsible for microcephaly may exist close to BPES gene. BPES, microcephaly, developmental retardation, and primary amenorrhea might constitute a contiguous gene syndrome.

Abnormalities, Multiple↗
PubMed2002

Amish lethal microcephaly: a new metabolic disorder with severe congenital microcephaly and 2-ketoglutaric aciduria.

A new metabolic disorder characterized by severe congenital microcephaly, death within the first year, and severe 2-ketoglutaric aciduria has been found among the Old-Order Amish of Lancaster County, Pennsylvania. Amish lethal microcephaly segregates as an autosomal recessive disorder and has an unusually high incidence of at least 1 in 500 births. When the infants are well, the urine organic acid profiles show isolated, extreme elevations of 2-ketoglutaric acid. However, during otherwise simple viral illnesses, the infants often develop a metabolic acidosis, which may follow a lethal course. Cranial magnetic resonance imaging of a single patient showed a smooth, immature brain similar to that of a 20-week fetus except for a moderate degree of cerebellar vermal hypoplasia. Assay of 2-ketoglutarate dehydrogenase in cultured lymphoblasts of one patient showed normal activity. Amish lethal microcephaly maps to 17q25 and may be caused by a defect in a mitochondrial inner membrane protein functioning as a 2-ketoglutarate transporter.

Ethnicity↗
PubMed2000

Congenital microcephaly detected by prenatal ultrasound: genetic aspects and clinical significance.

OBJECTIVE: The aim of this study was to analyze fetuses with prenatally diagnosed microcephaly including the nature of associated anomalies and the genetic-diagnostic implications. DESIGN: Retrospective study design. METHODS: A total of 30 fetuses with reliable dates and with prenatally diagnosed microcephaly as a common feature were analyzed. RESULTS: Microcephaly was diagnosed at a mean gestational age of 28 weeks. More than half of the fetuses were also small for gestational age. Five subsets of microcephaly emerged from this study: (1) isolated microcephaly (16.7%); (2) microcephaly due to holoprosencephaly (16.7%); (3) microcephaly associated with chromosomal disorders (23.3%); (4) microcephaly as part of a genetic syndrome (20.0%); and (5) microcephaly as part of multiple anomalies (23.3%). CONCLUSIONS: In 25 out of 30 infants microcephaly proved to be part of a complex problem, emphasizing the need of a meticulous search for structural anomalies and fetal karyotyping when biometric data are not according to gestational age. The etiologic heterogeneity and variability of microcephaly in genetic syndromes are among the more difficult issues in prenatal ultrasound in pregnancies either with an incidental finding of this anomaly, or in cases with a recurrence risk. The complex situations described in this study demonstrate the importance of follow up, post-mortem investigation and careful genetic counseling.

Abnormalities, Multiple↗
PubMed1990

Microcephaly: general considerations and aids to nosology.

Microcephaly is defined as an occipito-frontal head circumference (OFC) 2 or more standard deviations below the mean for age and sex using the new Roche et al. [Pediatrics 1987;79:706-712] charts, and corrected for parental OFC by the method of Weaver and Christian [J Pediatr 1980;96:990-994]. "Relative" microcephaly, i.e., a small head on a small child, may be associated with a much better intellectual prognosis than absolute microcephaly, although the average IQ of children with absolute microcephaly ascertained in a normal school system is normal when compared with that of appropriate control children. "Primary" microcephaly means an abnormal OFC at birth (corrected for gestational age and length), and "secondary" microcephaly a normal birth OFC with later, acquired microcephaly due to deceleration of brain growth reflecting infection, trauma, intoxication, metabolic disease, the Rett syndrome, or a true CNS degenerative disease. Some cases of syndromal microcephaly may be associated with normal intelligence including some "primordial dwarfs," children with Dubowitz syndrome, FAS, mild SC-Roberts syndrome, and an occasional Brachmann-de Lange individual. The nosology of (syndromal) microcephaly is extraordinarily complex and requires the assistance of special library resources and information retrieval expertise. At a minimum, it requires McKusick's Catalog of Mendelian Inheritance in Man (MIM); however, we find that our work is greatly enhanced by recently developed electronic databases such as MIM-online (OMIM), POSSUM, SYNDROME, and MEDLINE, as well. Three groups of syndromal and non-syndromal microcephaly are discussed selectively in order to illustrate the marvels of pleiotropy in human development and its abnormalities and the difficulties encountered in splitting and lumping entities with overlapping manifestations.

Abnormalities, Multiple↗
PubMed2003

Factors associated with microcephaly at school age in a very-low-birthweight population.

The neonatal predictors of microcephaly, defined as a head circumference <5th centile in children born preterm, has not been systematically assessed. Children were drawn from the Developmental Epidemiology Network (DEN) cohort of very low-birthweight children (VLBW: 500-1500g) born from 1991 to 1993 at three sites in the USA. Neurological assessments were carried out among 198 singleton children (mean age 6 years 8 months, SD 0.5 years). Ninety-six children (48.5%) were male. Microcephaly was observed in 30 children (15%) and, using multivariate analysis, it was found to be associated with gestational age <26 weeks and bronchopulmonary dysplasia (BPD). Sonography-defined white-matter damage (WMD, i.e. echolucency or echodensities) was not associated with increased odds of microcephaly, while occurrence of intraventricular hemorrhage (IVH) was in univariate but not multivariate analysis. In analyses that excluded children with IVH/WMD, odds of microcephaly increased in dose-related fashion according to number of days on ventilator: >5 days, OR=4.5; 95%CI=1.4 to 15; >10 days, OR=5.7; 95%CI=1.7 to 19; >15 days OR=8.3; 95% CI=2.3 to 29.2. Among children without BPD, microcephaly was not associated with differences in IQ, while IQ scores among children with BPD or any ventilation were disproportionately lower among those with microcephaly. In multivariate analyses predicting IQ at age 7 years, microcephaly was found to modify the association between neonatal lung disease and IQ.

Bronchopulmonary Dysplasia↗
PubMed1998

Microcephaly with chorioretinal degeneration.

PURPOSE: To describe the ophthalmologic findings and electroretinograms in patients with microcephaly and chorioretinal degeneration. METHODS: We reviewed the hospital records of 20 patients with microcephaly that was not part of a recognizable syndrome prior to initial referral to the institutional consultative practice of one of the authors (RGW). Twelve patients, all from separate families, were diagnosed as having microcephaly with chorioretinopathy. Ten of these patients had ISCEV-standard electroretinograms (ERG). RESULTS: No family history of microcephaly or retinal degeneration was found in any of our patients. Three patients had another family member with mental retardation. Three of the 12 were compatible with the autosomal dominant form of microcephaly with chorioretinopathy (MIM 156590), possibly as a new mutation. Eight patients, who had fundus findings of retinitis pigmentosa, were similar to the autosomal recessive form of microcephaly with chorioretinal degeneration (MIM 251270). The ERGs were moderately to severely subnormal for responses of both rods and cones. The retinal findings varied from no pigmentary changes, pigment clumping and bone spicules, pigmentary granularity, bull's eye maculopathy, choroidal and retinal atrophy, to lacunar depigmentation. Mental retardation was mild to profound. The abnormal findings from MRI/ CT brain scans (8 patients) were cerebellar atrophy (2), agenesis of cerebellar vermis (1), cortical atrophy (1), and pachygyria (1). Dysmorphic features were present in most patients. Chromosome studies were normal, except for one patient with ring chromosome 14. CONCLUSIONS: Although the patients reviewed in this study represent a heterogeneous group of disorders, ocular abnormalities, especially retinal degeneration, are frequent among patients with microcephaly.

Adolescent↗
PubMed1995

Difficulties in the prenatal diagnosis of microcephaly.

Our objective was to determine whether the diagnosis of microcephaly present at birth is apparent using standard biometry in the second trimester. Fetuses with prenatally suspected microcephaly (biparietal diameter > or = 3 standard deviations below mean) who had a first sonogram prior to 22 weeks' gestation and a confirmation of microcephaly after birth were included in the study. We excluded all fetuses who had neural tube defects or other major associated abnormality that would lead to a suspicion of microcephaly. We therefore included fetuses who either had normal-appearing brains sonographically or intracranial calcifications as the only sonographic abnormality seen prior to 22 weeks' gestation. Seven fetuses met these criteria. One fetus was diagnosed as having microcephaly prior to 22 weeks' gestation. The other six fetuses had a normal head size prior to 22 weeks' gestation and were diagnosed as having microcephaly at 27 weeks' gestation and later. Only one of the seven fetuses had a karyotypic abnormality. We conclude that the prenatal diagnosis of microcephaly is not excluded by normal biometry on second trimester sonography.

Adult↗
PubMed1987

Microcephaly: genetic counselling and antenatal diagnosis after the birth of an affected child.

We describe the clinical and genetic details of a series of microcephalic patients who were referred to the Genetic Counselling Service for the West of Scotland. There were 29 isolated cases of microcephaly and 9 families with recurrent microcephaly. The sib recurrence risk was 19%, which reflects the high incidence of autosomal recessive microcephaly in this series. There was evidence for several varieties of recessive microcephaly. The most frequent, affecting 5 sib pairs, was associated with spastic quadriplegia, seizures, and profound mental handicap. In 15 families with one microcephalic child, prenatal diagnosis by serial ultrasound scans was undertaken in 21 subsequent pregnancies. Four recurrences of microcephaly were detected in the third trimester and one recurrence was missed because no scans were performed after 24 wk gestation when the ultrasound measurements indicated satisfactory head growth. The main reason for late diagnosis of affected fetuses was that head growth did not slow appreciably until the last trimester. The high recurrence risk in this prospective series emphasizes the contribution of autosomal recessive inheritance of microcephaly amongst patients of our Genetic Counselling Service.

Female↗
PubMed1990

Prenatal diagnosis of autosomal dominant microcephaly and postnatal evaluation with magnetic resonance imaging.

A case of fetal autosomal dominant microcephaly was prenatally diagnosed with ultrasonography in a woman with previously undiagnosed microcephaly. At the time of initial ultrasonographic assessment, the mother was identified to have a markedly small cranium, consistent with maternal microcephaly. The ultrasonographic examination showed the fetal head size to be four standard deviations below the mean for gestational age. Gestational dating from the other biometric parameters and from the last menstrual period was consistent with 31 weeks' gestation. Neurosonographic evaluation of the fetus revealed no obvious structural abnormalities. Serial ultrasonographic examinations at 35 and 38 weeks' gestation showed no changes in the fetal head size. A 2.64 kg male fetus was delivered at term. Neonatal assessment showed the fetal head circumference to be less than the second percentile for gestational age. Neurologic assessment of the neonate with magnetic resonance imaging showed abnormal development of the brain, with small cerebellar and cerebral hemispheres, and pachygyria. These images are compared with the magnetic resonance images of the mother. Our findings of maternal and fetal microcephaly are consistent with autosomal dominant microcephaly. To our knowledge, this is the first report of the prenatal diagnosis of autosomal dominant microcephaly.

Adult↗
PubMed2003

Microcephaly: an epidemiologic analysis.

OBJECTIVE: This study was conducted to identify all risk factors that are associated with microcephaly and to quantify the magnitude of risk that is associated with these factors. STUDY DESIGN: This population-based case-control study used the Missouri Birth Defects Registry to identify 360 microcephaly cases and 3600 control cases during 1993 through 1999. Logistic regression was used to calculate adjusted odds ratios and 95% CIs. RESULTS: Significant risk factors for isolated microcephaly include alcohol use, inadequate weight gain during pregnancy, inadequate prenatal care, black race, and low education. Mothers with one previous live birth were protected against isolated microcephaly compared with nulliparous women. CONCLUSION: Our results suggest that microcephaly may arise from some preventable factors. These findings may be useful in aiding clinicians, patients, and policymakers in reducing the risk of microcephaly, a source of high perinatal mortality and morbidity rates.

Abnormalities, Multiple↗
PubMed2001

Congenital microcephaly: phenotypic features in a consecutive sample of newborn infants.

OBJECTIVE: We compared the prevalence of major and minor anomalies in a consecutive sample of newborn infants with congenital microcephaly with that among normocephalic infants. STUDY DESIGN: Head measurements from >19,000 liveborn infants at 1 hospital during the years 1991 and 1992 were reviewed. Infants whose head circumference was in the lowest quartile (n = 850) were remeasured by research assistants to identify all whose head circumference was 2 SD below the mean for gestational age; 106 infants with congenital microcephaly were identified. Infants with microcephaly (n = 65) and 294 infants in a control group were examined systematically for major malformations and minor physical features. RESULTS: Four (6.2%) of the 65 infants examined either had a major malformation or were considered dysmorphic. One of the 4 had a specific multiple malformation syndrome, and 1 dysmorphic infant had a rare metabolic defect. Overall, the infants with microcephaly did not have a higher frequency of minor anomalies. However, there was a higher frequency of frontal bossing, small chin, and short nose with anteverted nares, which was associated with small body size rather than microcephaly. CONCLUSIONS: Congenital microcephaly is infrequently accompanied by major malformations and occurs rarely as part of a recognizable syndrome.

Abnormalities, Multiple↗
PubMed2002

Significance of microcephaly among children with developmental disabilities.

To assess the clinical impact of microcephaly among children with developmental disabilities, we reviewed the charts of 1393 consecutive patients from birth to 5 years of age referred to our child development center. Comparisons were made between normal and low IQ microcephalic patients and between children with cerebral palsy with and without small head circumference. Microcephaly was detected in 15.4% of patients. Although mental retardation was more common among microcephalic children (P < .001), almost half had normal intelligence. Prematurity (P < .001), perinatal asphyxia (P < .001), small for gestational age (P < .001), respiratory distress syndrome (P < .001), and brain hemorrhage (P < .001) were associated with microcephaly. Hypotonia (P < .001) and spasticity (P < .001) were the most common neurologic findings. Cerebral palsy (P < .001), growth retardation (P < .001), epilepsy (P < .001), and strabismus (P < .001) were the main associated diagnoses found. Mental retardation was significantly more common among microcephalic patients with cerebral palsy than among normocephalic ones (P < .0004). Microcephaly is common among children evaluated for developmental disabilities. Many of these patients have normal or borderline IQ. Of several perinatal conditions associated with later microcephaly, respiratory distress syndrome and intraventricular hemorrhage show the strongest correlation. Mental retardation is not a risk factor for other neurologic complications in microcephalic children. However, in children with cerebral palsy, microcephaly is a risk factor for mental retardation.

Asphyxia Neonatorum↗
PubMedDate not supplied

An Italian family affected by autosomal dominant microcephaly with chorioretinal degeneration.

PURPOSE: We studied an Italian family affected by the autosomal dominant form of microcephaly and chorioretinal degeneration that was characterized by various degrees of clinical expression. METHODS: An ophthalmologic examination, including visual acuity, visual field testing, an electroretinogram, and fundus photography, and a neurologic examination, including neurodevelopmental status and neuroimaging studies, were performed for all subjects. Skeletal radiography, chromosome studies, and serologic investigations were also performed. RESULTS: In this family, only two of the six affected members had an association of microcephaly, myopia, and chorioretinal degeneration. The other family members showed microcephaly, slight mental retardation, and short stature, but not chorioretinopathy. CONCLUSIONS: The significant finding in members from this dominant pedigree of microcephaly was the association of short stature and high myopia, heretofore seen only in families with recessive microcephaly. These findings could be useful for genetic counseling in the apparently isolated forms of microcephaly with chorioretinopathy.

Adult↗
PubMed1984

Is a gene for microcephaly located on chromosome 1?

A 3-month-old boy with true microcephaly showed the same balanced reciprocal translocation 1q4p as his carrier mother. This reciprocal translocation had been transmitted for at least four generations. Different banding techniques allowed one to describe the rearrangement as: rcp t(1;4) (1pter----1q31::4p161----4pter; 4qter----4p153::1q321----1qter). On the other hand, the proband's father seemed to be a border-line mentally retarded and one of his relatives suffered from mental retardation of unknown origin. Taking into account all these results together with the current literature, it was concluded that the microcephaly appearing in our case could be due to the following two facts: (a) the father was an heterozygote for the gene for microcephaly, and (b) damage or a minute deletion on chromosome 1 between 1q31 and 1q321 bands could occur in the mother's family resulting in a mutation for microcephaly. If this was so, the gene for microcephaly should be located on chromosome 1 at the level of the 1q31-1q321 junction.

Adult↗