In humans, a single transverse palmar crease is a single crease that extends across the palm of the
hand
A hand is a prehensile, multi-fingered appendage located at the end of the forearm or forelimb of primates such as humans, chimpanzees, monkeys, and lemurs. A few other vertebrates such as the Koala#Characteristics, koala (which has two thumb#O ...
, formed by the fusion of the two
palmar creases. Although it is found more frequently in persons with several abnormal medical conditions, it is not predictive of any of these conditions since it is also found in persons with no abnormal medical conditions.
This crease is estimated to occur in 1.5-3% of the general population, although it is more common in East Asian and Native American populations.
Former name
Because it resembles the usual condition of non-human
simian
The simians, anthropoids, or higher primates are an infraorder (Simiiformes ) of primates containing all animals traditionally called monkeys and apes. More precisely, they consist of the parvorders New World monkey, Platyrrhini (New World mon ...
s, it was, in the past, called the simian crease or simian line. These terms have widely fallen out of favor due to their pejorative connotation.
Medical significance
This crease is found in 45% of people with
down syndrome.
The presence of a single transverse palmar has been associated with several abnormal medical conditions—that is, it is found at a higher than 1.5% frequency, but in all of these conditions, many do not have this crease. Examples of conditions with such an association are
fetal alcohol syndrome
Fetal alcohol spectrum disorders (FASDs) are a group of conditions that can occur in a person who is exposed to alcohol during gestation. FASD affects 1 in 20 Americans, but is highly misdiagnosed and underdiagnosed.
The several forms of the ...
and the genetic chromosomal abnormalities, such as
Down syndrome (
chromosome 21
Chromosome 21 is one of the 23 pairs of chromosomes in humans. Chromosome 21 is both the smallest human autosome and chromosome, with 46.7 million base pairs (the building material of DNA) representing about 1.5 percent of the total DNA in cell ...
),
cri du chat syndrome (
chromosome 5),
Klinefelter syndrome
Klinefelter syndrome (KS), also known as 47,XXY, is a chromosome anomaly where a male has an extra X chromosome. These complications commonly include infertility and small, poorly functioning testicles (if present). These symptoms are often n ...
,
Wolf–Hirschhorn syndrome
Wolf–Hirschhorn syndrome (WHS) is a chromosomal deletion syndrome resulting from a partial deletion on the short arm of chromosome 4 el(4)(p16.3) Features include a distinct craniofacial phenotype and intellectual disability.
Signs and sympt ...
,
Noonan syndrome (
chromosome 12
Chromosome 12 is one of the 23 pairs of chromosomes in humans. People normally have two copies of this chromosome. Chromosome 12 spans about 133 million base pairs (the building material of DNA) and represents between 4 and 4.5 percent of the tot ...
),
Patau syndrome
Patau syndrome is a syndrome caused by a chromosomal abnormality, in which some or all of the cells of the body contain extra genetic material from chromosome 13. The extra genetic material disrupts normal development, causing multiple and co ...
(
chromosome 13
Chromosome 13 is one of the 23 pairs of chromosomes in humans. People normally have two copies of this chromosome. Chromosome 13 spans about 113 million base pairs (the building material of DNA) and represents between 3.5 and 4% of the total DNA i ...
),
IDIC 15/Dup15q (
chromosome 15
Chromosome 15 is one of the 23 pairs of chromosomes in humans. People normally have two copies of this chromosome. Chromosome 15 spans about 99.7 million base pairs (the building material of DNA) and represents between 3% and 3.5% of the total DNA ...
),
Edward's syndrome (
chromosome 18
Chromosome 18 is one of the 23 pairs of chromosomes in humans. People normally have two copies of this chromosome. Chromosome 18 spans about 80 million base pairs (the building material of DNA) and represents about 2.5 percent of the total DNA in ...
), and
Aarskog–Scott syndrome (X-linked recessive), or autosomal recessive disorder, such as
leukocyte adhesion deficiency-2 (LAD2). A unilateral single palmar crease was also reported in a case of
chromosome 9 mutation causing
nevoid basal cell carcinoma syndrome and
Robinow syndrome
Robinow syndrome is an extremely rare genetic disorder characterized by short-limbed dwarfism, abnormalities in the head, face, and external sex organ, genitalia, and vertebrae, vertebral segmentation. The disorder was first described in 1969 by h ...
. It is also sometimes found on the hands of the affected side of patients with
Poland syndrome and
craniosynostosis
Craniosynostosis is a condition in which one or more of the fibrous sutures in a young infant's skull prematurely fuses by turning into bone (ossification), thereby changing the growth pattern of the skull. Because the skull cannot expand perpe ...
.
A 1971 study refutes the hypothesis that the phenomenon is caused by fetal hand movement: the appearance of the crease occurs around the second month of gestation before the digital movement phase in the womb begins.
See also
*
Dermatoglyphics
References
External links
{{Use dmy dates, date=April 2017
Hand
Down syndrome