High-resolution array CGH defines critical regions and candidate genes for microcephaly, abnormalities of the corpus callosum, and seizure phenotypes in patients with microdeletions of 1q43q44.

Microdeletions of 1q43q44 result in a recognizable clinical disorder characterized by moderate to severe intellectual disability (ID) with limited or no expressive speech, characteristic facial features, hand and foot anomalies, microcephaly (MIC), abnormalities (agenesis/hypogenesis) of the corpus callosum (ACC), and seizures (SZR). Critical regions have been proposed for some of the more prominent features of this disorder such as MIC and ACC, yet conflicting data have prevented precise determination of the causative genes. In this study, the largest of pure interstitial and terminal deletions of 1q43q44 to date, we characterized 22 individuals by high-resolution oligonucleotide microarray-based comparative genomic hybridization. We propose critical regions and candidate genes for the MIC, ACC, and SZR phenotypes associated with this microdeletion syndrome. Three cases with MIC had small overlapping or intragenic deletions of AKT3, an isoform of the protein kinase B family. The deletion of only AKT3 in two cases implicates haploinsufficiency of this gene in the MIC phenotype. Likewise, based on the smallest region of overlap among the affected individuals, we suggest a critical region for ACC that contains ZNF238, a transcriptional and chromatin regulator highly expressed in the developing and adult brain. Finally, we describe a critical region for the SZR phenotype which contains three genes (FAM36A, C1ORF199, and HNRNPU). Although ~90% of cases in this study and in the literature fit these proposed models, the existence of phenotypic variability suggests other mechanisms such as variable expressivity, incomplete penetrance, position effects, or multigenic factors could account for additional complexity in some cases.

Cold-induced sweating syndrome: CISS1 and CISS2: manifestations from infancy to adulthood. Four new cases.

Cold-induced sweating syndrome (CISS), a rare autosomal recessive disorder, is genetically heterogeneous. Deficiency of the CRLF1 and the CLCF1 gene functions results in CISS1 and CISS2, respectively. So far, only a single patient with CISS2 has been reported. Here we describe four new cases of CISS, two additional patients with CISS2 (confirming locus heterogeneity) and two patients with CISS1. Their case histories are given in detail to emphasize the striking similarity of their presentation, which makes a clinical differentiation impossible. All four cases had a uniform presentation in the neonatal period, much like Crisponi syndrome - inability to suckle and swallow due to facial and bulbar weakness; excessive startle and trismus-like facial contractions when crying or being handled; apnoeic spells; episodic unexplained fevers (up to 41 degrees C) and associated seizures or even sudden death; erythematous skin rashes; and camptodactyly. Thus it is evident that Crisponi syndrome is the pediatric manifestation of both CISS1 and CISS2. Signs abate during infancy and most children have a normal psychomotor development. During the first decade all children develop scoliosis and abnormal sweating which is the most disabling symptom in adulthood. We report that cold-induced sweating can be effectively treated. Detailed clinical observations, correlated with the findings from basic science research, may serve to elucidate the role(s) of this important cytokine complex in embryonic and postnatal development.

Use of magnetic resonance imaging to measure facial soft tissue depth.

OBJECTIVE: To investigate the feasibility of using magnetic resonance imaging to estimate facial tissue depth at standard anthropological facial landmarks. DESIGN: Standard facial landmarks were marked with magnetic resonance imaging opaque markers on 10 normal subjects. Three observers estimated facial tissue depth at these landmarks on up to three separate occasions, and comparisons were made among the observers. SETTING: The study was conducted with volunteers at the University of Alberta Biomechanical Engineering unit. PARTICIPANTS: The volunteers were healthy individuals of both sexes between the ages of 18 and 30 years. MAIN OUTCOME MEASURES: The technical error of measurement among observers was used as the main indicator of precision of measurement. RESULTS: Measurements of tissue depth showed tolerable technical error of measurement and were precisely measured within and among observers. CONCLUSIONS: Magnetic resonance images can be used to estimate tissue depth in human faces with precision.

Vitiligo-spasticity syndrome: new case.

Vitiligo-spastic syndrome is a very characteristic syndrome that is both clinically and genetically heterogeneous. Most cases have been reported previously in Arab populations. A case in a patient of North European white extraction is reported and compared with previously reported cases.

Soft tissue facial resemblance in families and syndrome-affected individuals.

We investigated soft tissue facial resemblance among relatives with or without syndromes and among related and unrelated individuals diagnosed with the same syndrome. Using correlation coefficients, we compared facial landmark (i.e., three-dimensional coordinate) positions and measurements gained by photogrammetry in various combinations of normal and syndrome-affected individuals. There were fewer significant correlations for the three-dimensional coordinates and measurements between the normal parent-normal child pairs than for the normal sib pairs. There was no discernible pattern for the single measurements in the parent-child pairs, whereas all of the midline vertical measurements were significantly positively correlated in the normal sib pairs. Significant correlations were always positive in all sib comparisons, but ranged from negative to positive in all parent-child correlations. The shared environment of sibs was a possible explanation for their greater resemblance in comparison with parent-child pairs. We also had measurements from 11 subjects (related and unrelated) diagnosed with one of four syndromes, and we used these to compare individuals with the same syndrome by calculating correlation coefficients based on all available pairs of measurements. The highest significant positive correlations were found for related individuals with the same syndrome (0.72 to 0.83). Unrelated individuals with the same syndrome also had significant positive correlations, but they were lower (0.35 to 0.65). We therefore inferred that the genetic similarities between unrelated individuals with syndromes played a role in the resemblance between them, and that common genes and environment in related individuals further contributed to the high correlations found for them.

Preservation of the morphological and molecular stability of embryonic tissues.

There is presently great interest in using early embryonic tissues, particularly human tissue, for studies of protein and gene expression. Embryonic human tissue is very fragile, and delays often occur before it can be properly prepared for scientific study. Using chick embryos, we have studied the effects of delaying fixation or biochemical isolation on the preservation of cytological characteristics and biochemical molecules. Our study shows that by 60 min post-harvest, tissue morphology and immunofluorescence staining degrades, but the total mRNA profile remains stable. This study suggests that the time between removal of the tissue and fixation is critical to the results and that the critical time is much shorter for embryonic tissues than for more developed tissues. Our results have implications for all research where embryonic tissues are harvested but not processed immediately.

Genetic study of SOX9 in a case of campomelic dysplasia.

Campomelic dysplasia (CD) is a sporadic autosomal dominant syndrome that results in skeletal malformation and developmental abnormalities. Death usually occurs neonatally as a result of respiratory insufficiencies, but life expectancy varies depending on the severity of the phenotype. XY sex reversal is common in CD, and a range of genital defects is observed in males and females. CD is due to mutations in SOX9, a member of the SOX (SRY-related HMG box) gene family. SOX9 is a transcription factor involved in chondrogenesis and sex determination. We present a CD patient with a normal 46,XX karyotype and female phenotype. Single-stranded conformation polymorphism analysis of DNA from this CD patient demonstrated a single-stranded conformation polymorphism shift in the C-terminal region of SOX9. DNA sequencing showed a frameshift mutation resulting from the insertion of a single guanine residue in nucleotide region 1,453-1,456. This insertion mutation creates a mutant SOX9 open reading frame that is 201 nucleotides longer than the normal gene. It has been shown that the C-terminal region of SOX9 is responsible for the transactivating ability of the protein. The frameshift identified here affects approximately half of the protein region needed for full transactivating function. We hypothesize that residual SOX9 function may explain why this patient survived infancy.

Assessment of soft tissue facial asymmetry in medically normal and syndrome-affected individuals by analysis of landmarks and measurements.

We investigated soft tissue facial asymmetry in normal and syndrome-affected individuals ranging in age from 1 year to adulthood. The purposes of our study were to determine if facial asymmetry was greater in syndrome-affected individuals than in normal individuals and, if true, to distinguish those measurements that could be used in routine screening to identify the presence of syndromes in uncertain patients and, lastly, to investigate the causes of measurement asymmetry at the level of the landmarks. The last purpose was possible because we used a stereophotogrammetric method with which the three-dimensional (3D) landmark positions were obtained. In the statistically significantly different measurements, those from the right side were dominant, with one exception in each group, except normal males. In all groups the landmark analyses demonstrated the same trends, and while there was far less patterning in the 3D coordinates, these results were also consistent between the four groups. We compared the statistical findings of the 3D coordinates and measurements and found that there was no predictable relationship between significant findings in the landmarks and the measurements. In particular, we noted that statistical differences in measurements did not infer significant differences in the positions of the landmarks between the right and left sides of the face. Both the normal and syndrome-affected groups appeared to be equally canalized and similarly affected by developmental noise: When the bilateral measurement differences of each syndrome-affected subject were compared to the limits of normal asymmetry, less than 10% of the comparisons exceeded the norms.

Polytopic anomalies with agenesis of the lower vertebral column.

We describe clinical, pathological and radiological findings in 15 cases of sporadic and familial lower spine agenesis with additional anomalies of the axial skeleton and internal organs and speculate about the cause and pathogenesis of this malformation complex. We show that all of these findings are defects of blastogenesis, originate in the primary developmental field and/or the progenitor fields, thus representing polytopic field defects. This concept appears applicable in our cases and makes such terms such as "caudal regression syndrome" or "axial mesodermal dysplasia spectrum" redundant.

Technical note: Different techniques, different results--a comparison of photogrammetric and caliper-derived measurements.

The primary goal of our study was to compare photogrammetric measurements with caliper-derived measurements. We also looked at the difference between caliper-derived measurements that were taken with and without the landmarks marked. Thirteen facial measurements were repeated ten times on two adult subjects as follows: 1) Calipers were used to take the measurements before the landmarks were marked on each subject's face; 2) the landmarks were then marked with a black pencil, and the calipers were used to take the measurements again; and 3) images were taken of each subject with the markings left on the face, and the measurements were extracted from these images. Compared with the caliper-derived data taken with the landmarks marked, the photogrammetric means and standard deviations were typically larger, leading us to conclude that there was a systematic difference between the data. The generally greater variation in the photogrammetric measurements was ascribed to poor conditions, such as shadows, oblique markings, and unmarked landmarks. When the data gathered by caliper with and without the landmarks marked were compared, a systematic difference was suggested by the number of statistically significant t-test probabilities. Marking the landmarks reduced the standard deviations in some measurements by controlling two sources of variation: differing pressure on the skin and slippage of the calipers. Anthropologists, medical geneticists, and others who use measurements for diagnostic or classificatory purposes should be aware that data gathered by different techniques may yield different results.

Facial measurements in clinical genetics: How important are the instruments we use?

Prompted by our finding that a popular compendium of clinical measurements often suggests a transparent ruler as a suitable substitute for anthropometric calipers (which were typically used by the original researchers to collect the normative data), we compared facial measurements taken with a ruler and calipers. Our objectives were to compare facial measurement data taken with these instruments by two classes of observer: expert and inexperienced. Ten facial measurements were repeated on four medically normal women by one expert and one inexperienced observer. Both observers' data showed that the caliper-derived means were usually the larger, but, whereas the expert observer's caliper-derived data typically were the least variable, the novice observer had smaller standard deviations and ranges for the ruler-derived data. Statistically significant differences were found between the ruler- and caliper-derived data from both observers on all four subjects, except for subnasale-pogonion and stomion-pogonion. For the novice observer only, endocanthion-endocanthion, left exocanthion-endocanthion, and alare-alare were also nonsignificant. The calibrations of the sliding caliper and ruler were compared to determine if differences between them could explain the statistical results, but were the same. We concluded that the differences between the caliper- and ruler-derived measurements resulted because the ruler often could not be placed directly on the landmarks, as could the arms of the calipers. We recommend that clinicians interested in taking facial measurements to assess their patients consult the original publications for information on the techniques and instruments used so that reliable comparisons with the normative data can be made.

X-linked situs abnormalities result from mutations in ZIC3.

Vertebrates position unpaired organs of the chest and abdomen asymmetrically along the left-right (LR) body axis. Each structure comes to lie non-randomly with respect to the midline in an overall position designated situs solitus, exemplified in humans by placement of the heart, stomach and spleen consistently to the left. Aberrant LR axis development can lead to randomization of individual organ position (situs ambiguus) or to mirror-image reversal of all lateralized structures (situs inversus). Previously we mapped a locus for situs abnormalities in humans, HTX1, to Xq26.2 by linkage analysis in a single family (LR1) and by detection of a deletion in an unrelated situs ambiguus male (Family LR2; refs 2,3). From this chromosomal region we have positionally cloned ZIC3, a gene encoding a putative zinc-finger transcription factor. One frameshift, two missense and two nonsense mutations have been identified in familial and sporadic situs ambiguus. The frameshift allele is also associated with situs inversus among some heterozygous females, suggesting that ZIC3 functions in the earliest stages of LR-axis formation. ZIC3, which has not been previously implicated in vertebrate LR-axis development, is the first gene unequivocally associated with human situs abnormalities.

Maternal uniparental heterodisomy for chromosome 16: case report.

A patient with uniparental heterodisomy for chromosome 16 presented initially at prenatal diagnosis with a karyotype of 47, XX + 16 on chorionic villus sampling at 11 weeks gestation. The pregnancy was proceeding normally and follow up amniocentesis showed a normal female karyotype. At birth, the child was healthy, but had intrauterine growth retardation. She had unilateral talipes equinovarus and unilateral renal agenesis. Her growth had improved to within the normal range by age three years. On examination, she has epicanthic folds, a flat midface and almond shaped eyes. While these characteristics are not frankly abnormal, they are significantly different from other relatives in her family.

DK phocomelia phenotype (von Voss-Cherstvoy syndrome) caused by somatic mosaicism for del(13q).

DK phocomelia (von Voss-Cherstvoy syndrome) is a rare condition characterized by radial ray defects, occipital encephalocoele, and urogenital abnormalities. Lubinsky et al. [1994: Am J Med Genet 52:272-278] pointed out similarities between this and the del(13q) syndrome. To date, all reported cases of DK phocomelia have been apparently normal chromosomally. We report on a case of DK phocomelia in which the proposita had normal lymphocyte chromosomes, but was mosaic in fibroblasts for del(13)(q12). Fibroblast chromosomes studies on other cases of DK phocomelia have not been reported: this raises the possibility that some cases of DK phocomelia may be somatic mosaics for del(13)(q12).

Adams Oliver syndrome: a family with extreme variability in clinical expression.

We describe a mother and her 3 children with variable scalp defects and limb defects consistent with a diagnosis of Adams Oliver syndrome also presenting with additional anomalies including congenital heart disease, microcephaly, epilepsy, mental retardation, arrhinencephaly, hydrocephaly, anatomic bronchial anomalies, and renal anomalies. The clinical variation between the individuals is more pronounced than in previously reported families.