Molecular cytogenetic insights to the phylogenetic affinities of the giraffe (Giraffa camelopardalis) and pronghorn (Antilocapra americana).

Five families are traditionally recognized within higher ruminants (Pecora): Bovidae, Moschidae, Cervidae, Giraffidae and Antilocapridae. The phylogenetic relationships of Antilocapridae and Giraffidae within Pecora are, however, uncertain. While numerous fusions (mostly Robertsonian) have accumulated in the giraffe's karyotype (Giraffa camelopardalis, Giraffidae, 2n = 30), that of the pronghorn (Antilocapra americana, Antilocapridae, 2n = 58) is very similar to the hypothesised pecoran ancestral state (2n = 58).

Human balanced translocation and mouse gene inactivation implicate Basonuclin 2 in distal urethral development.

We studied a man with distal hypospadias, partial anomalous pulmonary venous return, mild limb-length inequality and a balanced translocation involving chromosomes 9 and 13. To gain insight into the etiology of his birth defects, we mapped the translocation breakpoints by high-resolution comparative genomic hybridization (CGH), using chromosome 9- and 13-specific tiling arrays to analyze genetic material from a spontaneously aborted fetus with unbalanced segregation of the translocation. The chromosome 13 breakpoint was ∼400  kb away from the nearest gene, but the chromosome 9 breakpoint fell within an intron of Basonuclin 2 (BNC2), a gene that encodes an evolutionarily conserved nuclear zinc-finger protein.

Cryptic chromosomal abnormalities identified in children with congenital heart disease.

Congenital heart disease (CHD) is the most common type of birth defect, and the etiology of most cases is unknown. CHD often occurs in association with other birth malformations, and only in a minority are disease-causing chromosomal abnormalities identified. We hypothesized that children with CHD and additional birth malformations have cryptic chromosomal abnormalities that might be uncovered using recently developed DNA microarray-based methodologies.

Cognitive and motor development during childhood in boys with Klinefelter syndrome.

The goal of this study was to expand the description of the cognitive development phenotype in boys with Klinefelter syndrome (47,XXY). We tested neuropsychological measures of memory, attention, visual-spatial abilities, visual-motor skills, and language. We examined the influence of age, handedness, genetic aspects (parental origin of the extra X chromosome, CAG(n) repeat length, and pattern of X inactivation), and previous testosterone treatment on cognition.

Phenotypic expansion of the supernumerary derivative (22) chromosome syndrome: VACTERL and Hirschsprung's disease.

Phenotypically healthy carriers of the balanced 11;22 translocation, the most frequent non-Robertsonian constitutional translocation known in human beings, are at risk of having a progeny with supernumerary derivative (22)t(11;22) syndrome [der(22) syndrome]. We present the cases of 2 male patients with supernumerary der(22) syndrome [47,XY,+der(22)t(11;22)(q23;q11.2)mat], yielding partial trisomy for 22pter-q11 and 11q23-qter.

A Turner syndrome neurocognitive phenotype maps to Xp22.3.

Background: Turner syndrome (TS) is associated with a neurocognitive phenotype that includes selective nonverbal deficits, e.g., impaired visual-spatial abilities.

The phenotype of short stature homeobox gene (SHOX) deficiency in childhood: contrasting children with Leri-Weill dyschondrosteosis and Turner syndrome.

Objective: To evaluate the growth disorder and phenotype in prepubertal children with Leri-Weill dyschondrosteosis (LWD), a dominantly inherited skeletal dysplasia, and to compare the findings from girls with Turner syndrome (TS).

Study Design: We studied the auxologic and phenotypic characteristics in 34 prepubertal LWD subjects (ages 1 to 10 years; 20 girls, 14 boys) with confirmed short stature homeobox-containing gene (SHOX) abnormalities. For comparative purposes, we evaluated similar physical and growth parameters in 76 girls with TS (ages 1 to 19 years) and 24 girls with LWD (ages 1 to 15 years) by using data collected from the postmarketing observational study, GeNeSIS.

Early androgen deficiency in infants and young boys with 47,XXY Klinefelter syndrome.

Background/aims: Klinefelter syndrome (KS) is characterized by the karyotype 47,XXY. In this study, we evaluated the physical and testicular failure phenotypes of infants and young boys with KS.

Methods: The evaluation included auxologic measurements, biologic indices of testicular function, and clinical assessment of muscle tone in 22 infants and young boys with KS, ages 1-23 months.

Androgen receptor CAGn repeat length influences phenotype of 47,XXY (Klinefelter) syndrome.

Context: Klinefelter syndrome (KS; 47,XXY karyotype and variants) is characterized by tall stature and testicular failure, with marked variation in severity of the phenotype. Previous studies have proposed that genetic factors including mosaicism, parental origin of the supernumerary X-chromosome, skewed X inactivation, and androgen receptor (AR) polyglutamine repeat length may contribute to phenotypic variability in KS.

Objective: The objective of this study was to investigate the roles of these genetic factors in the variability of the KS phenotype.

Lagomorphs (rabbits, pikas and hares) do not use telomere-directed replicative aging in vitro.

Telomere shortening is used for replicative aging in primates and ungulates but not rodents. We examined telomere biology in rabbits to expand the comparative biology of telomere-directed replicative senescence within mammals. The order Lagomorpha consists of two families; Leporidae and Ochotonidae.

Genetic mapping of an insertional hydrocephalus-inducing mutation allelic to hy3.

The transgenic mouse line OVE459 carries a transgene-induced insertional mutation resulting in autosomal recessive congenital hydrocephalus. Homozygous transgenic animals experience ventricular dilation with perinatal onset and are noticeably smaller than hemizygous or non-transgenic littermates within a few days after birth. Fluorescence in situ hybridization (FISH) revealed that the transgene inserted in a single locus on mouse Chromosome (chr) 8, region D2-E1.

Complete SHOX deficiency causes Langer mesomelic dysplasia.

The SHOX (short-stature homeobox-containing) gene encodes isoforms of a homeodomain transcription factor important in human limb development. SHOX haploinsufficiency has been implicated in three human growth disorders: Turner syndrome, idiopathic short stature, and Leri-Weill dyschondrosteosis. Langer mesomelic dysplasia is thought to be the homozygous form of dyschondrosteosis.