What are the other Names for this Condition? (Also known as/Synonyms)

• X-linked Tetraamelia-Multiple Malformations Syndrome
• Zimmer Taub Sova Syndrome
• Zimmer Phocomelia

What is X-Linked Tetra-Amelia with Multiple Malformations Syndrome? (Definition/Background Information)

• X-Linked Tetra-Amelia with Multiple Malformations Syndrome is an extremely rare mostly lethal congenital disorder characterized by absence of all four limbs and frequent associated major malformations involving the head, face, eyes, skeleton, heart, lungs, anus, urogenital, and central nervous systems
• The majority of cases are reported in individuals of middle Eastern descent 
• The syndrome is inherited in an X-linked recessive manner

(Source: Tetraamelia-multiple malformations syndrome; Orphanet, National Institute of Health and Medical Research (INSERM), Paris.)

Who gets X-Linked Tetra-Amelia with Multiple Malformations Syndrome? (Age and Sex Distribution)

• X-Linked Tetra-Amelia with Multiple Malformations Syndrome is a rare congenital disorder. The presentation of symptoms may occur at birth
• X-Linked Tetra-Amelia with Multiple Malformations Syndrome predominantly affects the male gender
• Worldwide, individuals of all racial and ethnic groups may be affected by this disorder

What are the Risk Factors? (Predisposing factors)

• A positive family history may be an important risk factor, since X-Linked Tetra-Amelia with Multiple Malformations Syndrome can be inherited
• Being a child of parents who are close blood relatives (such as first cousins) increases the risk of being born with X-Linked Tetra-Amelia with Multiple Malformations Syndrome

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of X-Linked Tetra-Amelia with Multiple Malformations Syndrome? (Etiology)

• The exact gene on the X chromosome that causes X-Linked Tetra-Amelia with Multiple Malformations Syndrome is not known at the present time
• X-Linked Tetra-Amelia with Multiple Malformations Syndrome is inherited in an X-linked recessive manner

X-linked recessive pattern of inheritance: The gene associated with this condition is located on the X chromosome, which is one of the two sex chromosomes. In males (who have only one X chromosome), one altered copy of the gene in each cell is sufficient to cause the condition. In females (who have two X chromosomes), a mutation would have to occur in both copies of the gene to cause the disorder. Because it is unlikely that females will have two altered copies of this gene, males are affected by X-linked recessive disorders much more frequently than females. A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons

What are the Signs and Symptoms of X-Linked Tetra-Amelia with Multiple Malformations Syndrome?

The signs and symptoms of X-Linked Tetra-Amelia with Multiple Malformations Syndrome may include the following:

Very frequently present symptoms in 80-99% of the cases:

• Aplasia/Hypoplasia involving the nose
• Aplasia/Hypoplasia involving the pelvis
• Aplasia/Hypoplasia of the lungs
• Hydrocephalus
• Microtia
• Oral cleft
• Polyhydramnios
• Tetraamelia

Frequently present symptoms in 30-79% of the cases:

• Abnormal lung lobation
• Abnormality of the larynx
• Abnormally ossified vertebrae
• Agenesis of corpus callosum
• Anal atresia
• Aplasia/hypoplasia of the nipples
• Cataract
• Cryptorchidism
• Iris coloboma
• Microcornea
• Micrognathia
• Microphthalmia
• Missing ribs
• Multicystic kidney dysplasia
• Narrow mouth
• Optic atrophy
• Septo-optic dysplasia
• Tracheal stenosis
• Vaginal atresia

(Source: X-Linked Tetra-Amelia with Multiple Malformations Syndrome; Genetic and Rare Diseases Information Center (GARD) of National Center for Advancing Translational Sciences (NCATS), USA.)

How is X-Linked Tetra-Amelia with Multiple Malformations Syndrome Diagnosed?

X-Linked Tetra-Amelia with Multiple Malformations Syndrome is diagnosed on the basis of the following information:

• Complete physical examination
• Thorough medical history evaluation
• Assessment of signs and symptoms
• Laboratory tests
• Imaging studies
• Biopsy studies, if necessary

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of X-Linked Tetra-Amelia with Multiple Malformations Syndrome?

The complications of X-Linked Tetra-Amelia with Multiple Malformations Syndrome may include:

• Failure to thrive
• Extreme breathing difficulties
• Seizures, due to hydrocephalus

Complications may occur with or without treatment, and in some cases, due to treatment also.

How is X-Linked Tetra-Amelia with Multiple Malformations Syndrome Treated?

There is no cure for X-Linked Tetra-Amelia with Multiple Malformations Syndrome, since it is a genetic condition. The treatment is usually given to manage the signs and symptoms and any complication that develops

How can X-Linked Tetra-Amelia with Multiple Malformations Syndrome be Prevented?

• X-Linked Tetra-Amelia with Multiple Malformations Syndrome may not be preventable, since it is a genetic disorder
• If there is a family history of the condition, then genetic counseling will help assess risks, before planning for a child
• Active research is currently being performed to explore the possibilities for treatment and prevention of inherited and acquired genetic disorders
• Regular medical screening at periodic intervals with tests and physical examinations are recommended

What is the Prognosis of X-Linked Tetra-Amelia with Multiple Malformations Syndrome? (Outcomes/Resolutions)

The prognosis of X-Linked Tetra-Amelia with Multiple Malformations Syndrome is poor, with babies succumbing to the disorder soon after birth

Additional and Relevant Useful Information for X-Linked Tetra-Amelia with Multiple Malformations Syndrome:

The following DoveMed website link is a useful resource for additional information:

http://www.dovemed.com/diseases-conditions/rare-disorders/