Rare Variation (rare + variation)

Distribution by Scientific Domains


Selected Abstracts


Rare variations of the left subclavian artery

CLINICAL ANATOMY, Issue 5 2005
Faysal A. Saadeh
Abstract The subclavian artery is a major constituent of the blood circulatory system. Its position in the root of the neck and its course through the interscalene triangle are significant. Its branches supply divers areas in the body from the brain to the thorax. This case report describes an unusual range of anatomical variations of the course of the left subclavian artery, the origin, and absence of some of its branches and the concomitant abnormal course of the phrenic nerve. Clinical syndromes related to certain variations are reviewed. Clin. Anat. 18:370,372, 2005. © 2005 Wiley-Liss, Inc. [source]


Absence of the celiac trunk: Case report and review of the literature

CLINICAL ANATOMY, Issue 4 2008
Shuang-Qin Yi
Abstract The authors report a rare variation of the absence of the celiac trunk in a Japanese cadaver, with the left gastric, splenic, common hepatic, and superior mesenteric arteries arising independently from the abdominal aorta in the routine dissection of a 95-year-old Japanese male cadaver. The incidence and developmental and clinical significance of this variation is discussed with a detailed review of the literature. Knowledge of such case has important clinical significance in an abdominal operation or invasive arterial procedure, that is, Appleby procedure and liver transplantation, laparoscopic surgery, and radiological procedures in the upper abdomen. Clin. Anat. 21:283,286, 2008. © 2008 Wiley-Liss, Inc. [source]


An unusual course of the left recurrent laryngeal nerve

CLINICAL ANATOMY, Issue 3 2007
Amir A. Khaki
Abstract Variation in the course of the left recurrent laryngeal nerve is seemingly very rare. During the routine dissection of an adult male cadaver, the entire left recurrent laryngeal nerve after branching from the left vagus nerve was noted to travel medial to the ligamentum arteriosum. We hypothesize that this rare variation may occur, if the left recurrent laryngeal nerve passes inferior to the fifth rather than the sixth aortic arch during embryological development. As our case report demonstrates, the relationship between the ligamentum arteriosum and the left recurrent laryngeal nerve is not absolute. Although seemingly rare, cardiothoracic surgeons must consider variations of the left recurrent laryngeal nerve during surgical procedures in the region of the ligamentum arteriosum in order to minimize potential postoperative complications. Clin. Anat. 20:344,346, 2007. © 2006 Wiley-Liss, Inc. [source]


A Genome-wide Association Study of Autism Reveals a Common Novel Risk Locus at 5p14.1

ANNALS OF HUMAN GENETICS, Issue 3 2009
Deqiong Ma
Summary Although autism is one of the most heritable neuropsychiatric disorders, its underlying genetic architecture has largely eluded description. To comprehensively examine the hypothesis that common variation is important in autism, we performed a genome-wide association study (GWAS) using a discovery dataset of 438 autistic Caucasian families and the Illumina Human 1M beadchip. 96 single nucleotide polymorphisms (SNPs) demonstrated strong association with autism risk (p-value < 0.0001). The validation of the top 96 SNPs was performed using an independent dataset of 487 Caucasian autism families genotyped on the 550K Illumina BeadChip. A novel region on chromosome 5p14.1 showed significance in both the discovery and validation datasets. Joint analysis of all SNPs in this region identified 8 SNPs having improved p-values (3.24E-04 to 3.40E-06) than in either dataset alone. Our findings demonstrate that in addition to multiple rare variations, part of the complex genetic architecture of autism involves common variation. [source]


Levator palpebrae superioris muscle in human fetuses: Anatomical findings and their clinical relevance

CLINICAL ANATOMY, Issue 7 2005
J. Plock
Abstract Accessory medial muscular bellies of the levator palpebrae superioris muscle and broad lateral insertion of its aponeurosis into tissue near the lacrimal gland have been reported as rare variations in adults. The anatomy of this muscle was studied in orbits of ten human fetuses between the 5th and 10th months of gestation. In each of the dissected orbits, the levator palpebrae superioris muscle had a broad lateral insertion into the capsule of the lacrimal gland or the periorbita, in this period of development. In addition, medial accessory muscles of the levator or singular muscle fibers within fibrous bands that inserted near the trochlear region and the medial portion of the upper eyelid were present in 70% of the fetuses, either unilaterally or bilaterally. These findings demonstrate new unreported aspects of levator palpebrae superioris development and morphology. Our findings suggest that an initial broad anterior primary anlage of the muscle is followed by secondary atrophy of lesser used marginal portions of this muscle, which are replaced by delicate connective tissue. These findings might force new considerations about diagnostic and therapeutic approaches to congenital mobility disorders of the levator palpebrae superioris muscle, such as blepharoptosis or eyelid retraction. The clinical relevance of our results are discussed along with a review of the embryogenesis of extraocular muscles and soft tissue of the orbit. Clin. Anat. 18:473,480, 2005. © 2005 Wiley-Liss, Inc. [source]