A systematic review of MRI studies of language development from birth to 2 years of age

Neurocognitive functions supporting language development start to develop well before first words are spoken during the first years of life. This process coincides with the initial growth spurt of the brain. While the core components of the language network are well characterized in adults and children, the initial neural correlates of language skills are still relatively unknown. We reviewed 10 studies identified via a systematic search that combined magnetic resonance imaging and language‐related measures in healthy infants from birth to 2 years of age. We aimed to describe the current knowledge as well as point out viable future directions for similar studies. Expectedly, the implicated cerebral areas included many established components of the language networks, including frontal and temporal regions. A volumetric leftward asymmetry of the brain was suggested as a determinant of language skills, yet with marked interindividual variation. Overall, temporal and frontal brain volumes associated positively with language skills. Positive associations were described between the maturation of language related white matter tracts and language skills. The language networks showed adult‐like structural similarities already in neonates, with weaker asymmetry compared to adults. In summary, we found some evidence that the language circuit described in older age groups is also associated to language skills during the first 2 years of life. However, across the reviewed studies there were no systematic neural correlates of language skills, which is partly explained by a modest number of studies, scattered representation of ages in measurements and the variance in the used methods.     

The relationship between brain weight and head circumference from birth to age 18 years

A relation between head circumference and brain weight of humans is generally believed to exist, but the literature contains only two studies which exhibit a quantitative aspect of the relation, showing that brain weight is proportional to the cube of the head circumference from birth through age 3.5 years. By assembling data from autopsy records, we have been able to show that this cubic relationship holds through brain maturation at around age 18 years.     

11q- syndrome: three cases and a review of the literature.

We report on three children with de novo terminal deletions of the long arm of chromosome 11 (11q-) and breakpoints in 11q23-q24. Eighty-nine other patients with partial monosomy 11q have been reported and were reviewed by us. Salient features of 11q- syndrome are psychomotor retardation, trigonocephaly, telecanthus/hypertelorism, broad depressed nasal bridge, micrognathia, low set abnormal ears, cardiac anomalies and hand/foot anomalies. Renal agenesis and anal atresia are reported first here. Supratentorial white matter abnormality on CT and MRI present in our second patient was reported in three patients. Increased mortality is caused by cardiac anomalies. A third of all patients with partial monosomy 11q had thrombocytopenia or pancytopenia and this seems to be related to the absence of band 11q23-q24. Seventy-six percent of patients have de novo deletions with breakpoints in 11q21-q25. There is no obvious correlation between the length of the deleted segment and the severity of the symptoms. In unbalanced chromosomal patterns with deletions of 11q involving bands 11q23-q24 the typical phenotype of 11q- syndrome remains recognizable. Deletions distal to 11q24.1 do not produce the typical 11q- syndrome.     

Rubinstein-Taybi syndrome: Clinical profile of 11 patients and review of literature

BACKGROUND:

Rubinstein-Taybi syndrome (RSTS) is a rare congenital neurodevelopmental disorder, characterized by postnatal growth deficiency, typical dysmorphic features, broad thumbs and toes, and mental retardation. Very few cases are reported in literature from developing countries. Diagnosis is often delayed due to non-familiarity with the characteristic features of this syndrome.

AIMS:

To report 11 cases of RSTS and to review the current literature.

SETTINGS AND DESIGN:

Retrospective study conducted in genetic and metabolic unit of a tertiary care teaching hospital in north India over a period of 3½ years.

MATERIALS AND METHODS:

11 patients with diagnosis of RSTS were identified, and their case sheets were reviewed.

RESULTS:

Developmental delay was presenting complaint in 10 patients, and seizure in 1 case. 7 patients had microcephaly (head circumference below −3 SD), and a prominent beaked nose was seen in 9 patients. The intelligence quotient (IQ) varied from 22-62 in 7 patients who had mental retardation. The most notable features in hands were broadness, shortening, and flattening of the distal phalanx of thumbs or great toes. Additionally, we also noted webbing of neck, microphthalmia, and pachygyria (on MRI brain) in 1 patient each.

CONCLUSIONS:

The diagnosis of RSTS is primarily clinical and based on characteristic phenotype that is often combined with a variety of somatic anomalies. An early diagnosis facilitates appropriate genetic counseling and in planning the management.     

Genetic and environmental contributions to weight, height, and BMI from birth to 19 years of age: an international study of over 12,000 twin pairs

Objective

To examine the genetic and environmental influences on variances in weight, height, and BMI, from birth through 19 years of age, in boys and girls from three continents.

Design and Settings

Cross-sectional twin study. Data obtained from a total of 23 twin birth-cohorts from four countries: Canada, Sweden, Denmark, and Australia. Participants were Monozygotic (MZ) and dizygotic (DZ) (same- and opposite-sex) twin pairs with data available for both height and weight at a given age, from birth through 19 years of age. Approximately 24,036 children were included in the analyses.

Results

Heritability for body weight, height, and BMI was low at birth (between 6.4 and 8.7% for boys, and between 4.8 and 7.9% for girls) but increased over time, accounting for close to half or more of the variance in body weight and BMI after 5 months of age in both sexes. Common environmental influences on all body measures were high at birth (between 74.1–85.9% in all measures for boys, and between 74.2 and 87.3% in all measures for girls) and markedly reduced over time. For body height, the effect of the common environment remained significant for a longer period during early childhood (up through 12 years of age). Sex-limitation of genetic and shared environmental effects was observed.

Conclusion

Genetics appear to play an increasingly important role in explaining the variation in weight, height, and BMI from early childhood to late adolescence, particularly in boys. Common environmental factors exert their strongest and most independent influence specifically in pre-adolescent years and more significantly in girls. These findings emphasize the need to target family and social environmental interventions in early childhood years, especially for females. As gene-environment correlation and interaction is likely, it is also necessary to identify the genetic variants that may predispose individuals to obesity.     

Social development of bonnet macaques from six months to three years of age: A longitudinal study

Observations of age-sex class associations of three young female and five young male bonnet macaques born in the spring, 1975, were taken semiannually over three years beginning in the fall, 1975. Analysis reveals several patterns: (1) both males and females show continuous decline in association with age mates; (2) solitary time of females peaks at 1.5 years after which they begin to associate with adult females; (3) solitary time of males peaks at 2.5 years after which they associate predominantly with sub-adult males; (4) both males and females showed higher association with juveniles of the same sex than of opposite sex; and (5) both males and females showed annual cycles of association with some age-sex classes. These results are best understood with reference to the natural breeding cycle of the animals and the different life histories of male and female macaques in the wild.     

Characteristics of the ensemble organization of the human cerebral cortex from birth to 20 years of age

When studying frontal, somatosensory and visual areas of the human cerebral cortex from birth up to 20 years of age in year-to-year intervals, it has been stated that by birth in neocortex all components of the neuron-glio-vascular ensembles are presented. They are not connected in their composition. During the first year of life the size of all types of neurons increases, long-axonal basket neurons differentiate, fasciculi of radial fibers become thick. By 3 years of life in the ensembles the neurons are definitely grouped as clusters. Sizes of spindle-like and satellite neurons increase; they distribute their axonal collaterals vertically, horizontally and in frontal-posterior direction. By 5-6 years of age the horizontal connection system becomes more complex at the expense of longitudinal growth and ramification of lateral and basal dendrites of the pyramidal neurons. In the section transversal areas occupied with cell groups increase. By 9-10 years of age the pyramidal neurons reach their greatest size. By 12-14 years of age the fibrillar component of the cortex increases considerably, inter- and intraensemble horizontal connections become more complex, the system of local connections becomes more plastic owing to development of short-axonal basket-like neurons. By 16-18 years of age the ensemble cortical organization in its main parameters of architectonics reaches the level specific for mature persons.     

The epidemiology of soil-transmitted helminth infections in children up to 8 years of age: Findings from an Ecuadorian birth cohort

BackgroundThere are few prospective longitudinal studies of soil-transmitted helminth (STH) infections during early childhood. We studied the epidemiology of and risk factors for soil-transmitted helminth infections from birth to 8 years of age in tropical Ecuador.Methods2,404 newborns were followed to 8 years of age with periodic stool sample collections. Stool samples were collected also from household members at the time of the child’s birth and examined by microscopy. Data on social, environmental, and demographic characteristics were collected by maternal questionnaire. Associations between potential risk factors and STH infections were estimated using generalized estimated equations applied to longitudinal binary outcomes for presence or absence of infections at collection times.ResultsOf 2,404 children, 1,120 (46.6%) were infected with at least one STH infection during the first 8 years of life. The risk of A. lumbricoides (16.2%) was greatest at 3 years, while risks of any STH (25.1%) and T. trichiura (16.5%) peaked at 5 years. Factors significantly associated with any STH infection in multivariable analyses included age, day-care (OR 1.34, 95% CI 1.03–1.73), maternal Afro-Ecuadorian ethnicity (non-Afro vs. Afro, OR 0.55, 95% CI 0.43–0.70) and lower educational level (secondary vs. illiterate, OR 0.31, 95% CI 0.22–0.45)), household overcrowding (OR 1.53, 95% CI 1.21–1.94)), having a latrine rather than a water closet (WC vs. latrine, OR 0.77, 95% CI 0.62–0.95)), and STH infections among household members (OR 2.03, 95% CI 1.59–2.58)). T. trichiura was more associated with poverty (high vs. low socioeconomic status, OR, 0.63, 95% CI 0.40–0.99)] and presence of infected siblings in the household (OR 3.42, 95% CI 2.24–5.22).ConclusionSTH infections, principally with A. lumbricoides and T. trichiura, peaked between 3 and 5 years in this cohort of children in tropical Ecuador. STH infections among household members were an important determinant of infection risk and could be targeted for control and elimination strategies.     

Length and weight in rural Guatemalan Ladino children: birth to seven years of age.

The present study reports 5,029 length and weight measurements as well as percentile distributions for a mixed longitudinal series of 1,119 rural Guatemalan Ladino children. The study sample, birth through seven years, is representative of children in clinically good health, but of suboptimal nutrition. Boys are longer and heavier than girls over the age range. Guatemalan children of both sexes are smaller than American white children from Denver. Differences are least at birth, and increase through two years of age. Between two and five years, differences between the rural Guatemalan Ladino and Denver samples are rather stable, but then increase through seven years. Despite these differences there is a linear weight for length relationship which is the same across all preschool ages, both sexes, and for both the Guatemalan and Denver populations. This implies that age, sex, ethnic differences between the two groups compared, and mild-to-moderate protein-calorie malnutrition do not affect the relationship between weight and length in preschool children.     

Determinants of the sex ratio at birth: review of recent literature

The fact that more boys are born than girls (104-107 boys for every 100 girls) has been known since 1662. Factors determining the sex ratio at birth rate are of 2 kinds: factors determining the primary sex ratio, i.e., sex ratio at conception, and factors determining the survival of the embryo in utero. Y-bearing and X-bearing sperm may have different motility or different survival time. The age of the ovum at fertilization and the chemical balance of the female genital tract have an effect on sex ratio at conception. High levels of circulating gonadotropins may imply a lower sex ratio at birth as well as a higher rate of dizygotic twinning. Male conception also appears to be higher early and late in the menstrual cycle. The fact that women exposed to higher coital rates conceive earlier in the menstrual cycle may account for the greater number of boys born during wars. Prenatal male mortality is reportedly highest between gestational months 3-5, lower between months 6-8, and higher again st term. Also, immunological interaction between mother and embryo may account for some sex selective spontaneous abortions. 3 sociodemographic determinants of sex ratio at birth are thought to be maternal age, paternal age, and birth order. Higher prenatal male mortality may be correlated with socioeconomic conditions, since higher socioeconomic status lowers prenatal mortality in general. The effects of parental age, birth order, and parity are less clear. Race is also a factor, since the sex ratio at birth for blacks is lower (102-104) than for whites (106). 14 univariate and 19 multivariate studies of effects of maternal age, paternal age, parity, birth order, race, and socioeconomic status on sex ratio at birth, with sample sizes in the millions from various countries have been analyzed. More boys are born to younger parents, and lower order births have a higher proportion of males than do higher order births. In the multivariate analyses, when the effects of paternal and and birth order are controlled for, the effect of maternal age weakens, and the effect of paternal age appears to be stronger. The effect of birth order remains but is very small, and the effect of race persists independent of any effect of other variables. Maternal age, parity, and birth order are positively correlated with proportion of male stillbirths. The results of the multivariate analyses show all of the effects to be very small, but that maternal age has no effect on sex ratio at birth; paternal age and birth order have a negative effect, and the racial effect persists independent of any other effect. The racial effect is clearly biologically determined at conception because blacks have higher levels of circulating gonadotropin and therefore a higher probability of conceiving girls. Parents in higher socioeconomic classes are more likely to have sons, but the effect is largely due to the excess male mortality during most of the gestational period.     

Infant milk feeding influences adult bone health: a prospective study from birth to 32 years

Background

Peak bone mass, attained by early adulthood, is influenced by genetic and life-style factors. Early infant feeding and duration of breastfeeding in particular, associate with several health-related parameters in childhood. The aim of this study was to examine whether the effects of early infant feeding extend to peak bone mass and other bone health characteristics at adult age.

Methods and Findings

A cohort of 158 adults (76 males) born in Helsinki, Finland, 1975, prospectively followed up from birth, underwent physical examination and bone densitometry to study bone area, bone mineral content (BMC), and bone mineral density (BMD) at 32 years of age. Life-style factors relevant for bone health were recorded. For data analysis the cohort was divided into three equal-size groups according to the total duration of breastfeeding (BF): Short (≤3 months), Intermediate and Prolonged (≥7 months) BF groups. In males short BF is associated with higher bone area, BMC, and BMD compared to longer BF. Males in the Short BF group had on average 4.7% higher whole body BMD than males in the Prolonged BF group. In multivariate analysis, after controlling for multiple confounding factors, the influence of BF duration on adult bone characteristics persisted in males. Differences between the three feeding groups were observed in lumbar spine bone area and BMC, and whole body BMD (MANCOVA; p = 0.025, p = 0.013, and p = 0.048, respectively), favoring the Short BF group. In women no differences were observed.

Conclusions

In men, early infant milk feeding may have a significant impact on adult bone health. A potential explanation is that the calcium and phosphate contents were strikingly higher in formula milk and commercial cow milk/cow milk dilutions as opposed to human milk. Our novel finding merits further studies to determine means to ensure optimal bone mass development in infants with prolonged breastfeeding.