CD-ROM Today 1996 January/CD-ROM Today 1996 January.iso/dp/0391/03915.txt

Text File | 1994-01-17 | 9.0 KB | 214 lines

$Unique_ID{BRK03915}
$Pretitle{}
$Title{LADD Syndrome}
$Subject{LADD Syndrome Lacrimo-Auriculo-Dento-Digital Syndrome LADD
Levy-Hollister Syndrome Limb Malformations-Dento-Digital Syndrome
Ectrodactyly-Ectodermal Dysplasia-Clefting Syndrome Split-Hand Deformity
Ectodermal Dysplasias }
$Volume{}
$Log{}

Copyright (C) 1992 National Organization for Rare Disorders, Inc.

885:
LADD Syndrome

** IMPORTANT **
It is possible that the main title of the article (LADD Syndrome) is not
the name you expected.  Please check the SYNONYMS listing to find the
alternate name and disorder subdivisions covered by this article.

Synonyms

     Lacrimo-Auriculo-Dento-Digital Syndrome
     LADD
     Levy-Hollister Syndrome
     Limb Malformations-Dento-Digital Syndrome

Information on the following diseases can be found in the Related
Disorders section of this report:

     Ectrodactyly-Ectodermal Dysplasia-Clefting Syndrome
     Split-Hand Deformity
     Ectodermal Dysplasias

General Discussion

** REMINDER **
The Information contained in the Rare Disease Database is provided for
educational purposes only.  It should not be used for diagnostic or treatment
purposes.  If you wish to obtain more information about this disorder, please
contact your personal physician and/or the agencies listed in the "Resources"
section of this report.

LADD Syndrome is a rare genetic disorder inherited through an autosomal
dominant trait.  The major feature of this syndrome is malformations of the
upper limbs.  Other symptoms of the disorder may include:  malformations in
the network of structures of the eye that secretes tears and drains them from
the surface of the eyeball (Lacrimal malformations); abnormalities of the
teeth; small cupped ears; absent or underdeveloped salivary glands; hearing
loss; abnormalities of the sexual and urinary system of the body
(genitourinary) and/or unusual skin ridge patterns.

Symptoms

The most constant feature of LADD Syndrome is malformations of the upper
limbs.  Defects of the forearm have been found in all patients with LADD
Syndrome.  These defects may be:  shortening of one of the bones of the
forearm (radius or ulna) and/or the union of the bones of the forearm (radius
and ulna) forming a single bone (synostosis).

Other malformations of the upper limbs may be:  an absent or
underdeveloped thumb and/or second finger; three bones in the thumb instead
of the usual two; bending of the fifth finger to the side (clinodactyly);
and/or syndactyly (growing together) of the second and third fingers.

Malformations in the network of structures of the eye that secrete tears
and drain them from the surface of the eyeball (lacrimal malformations) have
been found in three quarters of the patients with LADD Syndrome.  These
malformations may be:  an abnormal passage from the tear sac to the nasal
opening; an underdeveloped or missing opening in the edge of each eyelid that
is linked to the tear duct (lacrimal puncta) and/or an obstruction of the
channel that carries tears from the tear sac to the nasal opening.

Other features found in the many of the patients with LADD Syndrome are:
small, cupped ears; hearing loss; less than the normal number of teeth;
abnormal enamel of the teeth; peg-shaped incisors; darkening of the teeth;
thinning of the enamel on the teeth; and/or absent or underdeveloped salivary
glands.

Symptoms that have been found in a small percentage of the patients with
LADD Syndrome have been:  malformations of the sexual and urinary system
(genitourinary malformations); unusual skin ridge patterns; absence of a
kidney; a condition where the urethra opens under the penis and/or hardening
of the kidney.

Causes

LADD Syndrome is inherited through an autosomal dominant trait.  There has
been one reported case of this disorder possibly occuring sporadically.
Human traits, including the classic genetic diseases, are the product of the
interaction of two genes, one received from the father and one from the
mother.  In dominant disorders a single copy of the disease gene (received
from either the mother or father) will be expressed "dominating" the other
normal gene and resulting in the appearance of the disease.  The risk of
transmitting the disorder from affected parent to offspring is fifty percent
for each pregnancy regardless of the sex of the resulting child.

Affected Population

LADD Syndrome affects males and females in equal numbers.  There have bee
approximately twelve cases of this disorder described in the medical
literature.  The majority of the reported cases have been in the Caucasian-
American and Mexican-American population.

Related Disorders

Symptoms of the following disorders can be similar to those of LADD Syndrome.
Comparisons may be useful for a differential diagnosis:

Ectrodactyly-Ectodermal Dysplasia-Clefting Syndrome is a genetic disorder
which may be characterized by an absence of fingers and/or toes
(ectrodactyly), an absence of tear ducts; cleft lip and/or palate; and sparse
scalp hair, lashes and eyebrows.  This disorder may be inherited through an
autosomal dominant trait.  (For more information on this disorder, choose
"Ectodermal Dysplasia" as your search term in the Rare Disease Database).

Split-Hand Deformity is a genetic disorder characterized by the absence
of fingers or parts of fingers, commonly occuring with a cleft of the hand.
This combination often gives the hand a claw-like appearance.  When a cleft
does occur it usually affects both hands and both feet.  There are many types
and combinations of deformities that appear in Split-Hand Deformity.  It is
believed that they are all the result of a common genetic defect that ranges
widely in severity.  This disorder is inherited through an autosomal dominant
trait.  (For more information on this disorder, choose "Split-Hand Deformity"
as your search term in the Rare Disease Database).

Ectodermal Dysplasias are a group of hereditary, nonprogressive syndromes
in which the affected tissue derives primarily from the ectodermal germ
layer.  The skin, its derivatives, and some other organs are involved.  A
predisposition to respiratory infections, due to a somewhat depressed immune
system and to defective mucous glands in parts of the respiratory tract, is
the most life threatening characteristic of this group of disorders.  The
various syndromes have different inheritance patterns.  (For more information
on this disorder, choose "Ectodermal Dysplasias" as your search term in the
Rare Disease Database).

Therapies:  Standard

Treatment of Ladd Syndrome is symptomatic and supportive.

When the network of structures of the eye that secretes tears and drain
them from the surface of the eyeball (lacrimal apparatus) has malformations,
surgery may be performed.

Dental care should be given on a regular basis.

Some patients with Ladd Syndrome may benefit from the use of hearing aids.

Genetic counseling may be of benefit for patients and their families.

Therapies:  Investigational

Research on birth defects and their causes is ongoing.  The National
Institutes of Health (NIH) is sponsoring the Human Genome Project which is
aimed at mapping every gene in the human body and learning why they sometimes
malfunction.  It is hoped that this new knowledge will lead to prevention and
treatment of birth defects in the future.

This disease entry is based upon medical information available through
January 1992.  Since NORD's resources are limited, it is not possible to keep
every entry in the Rare Disease Database completely current and accurate.
Please check with the agencies listed in the Resources section for the most
current information about this disorder.

Resources

For more information on LADD Syndrome, please contact:

     National Organization for Rare Disorders (NORD)
     P.O. Box 8923
     New Fairfield, CT  06812-1783
     [phone]

     International Skeletal Dysplasia
     ST. Joseph Hospital
     7620 York Road
     Towson, MD  21204
     [phone]

     The National Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
Information Clearinghouse
     Box AMS
     Bethesda, MD  20892
     [phone]

For Genetic Information and Genetic Counseling Referrals:

     March of Dimes Birth Defects Foundation
     1275 Mamaroneck Avenue
     White Plains, NY 10605
     [phone]

     Alliance of Genetic Support Groups
     35 Wisconsin Circle, Suite 440
     Chevy Chase, MD  20815
     (800) 336-GENE
     [phone]

References

MENDELIAN INHERITANCE IN MAN, 9th Ed.:  Victor A. McKusick, Editor:  Johns
Hopkins University Press, 1990.  Pp. 554.

SMITH'S RECOGNIZABLE PATTERNS OF HUMAN MALFORMATION, 4th Ed.:  Kenneth L.
Jones, M.D., Editor; W.B. Saunders Co., 1988.  Pp. 273.

BIRTH DEFECTS ENCYCLOPEDIA, Mary Louise Buyse, M.D., Editor-In-Chief;
Blackwell Scientific Publications, 1990.  Pp. 1024.

LACRIMO-AURICULO-DENTO-DIGITAL (LADD) SYNDROME WITH RENAL AND FOOT
ANOMALIES:  A.M. Roodhooft, et al.; Clin Genet (September, 1990, issue
38(3)).  Pp. 228-32.