Melnick-Needles Syndrome

What is Melnick-Needles syndrome?

Melnick-Needles syndrome is a disorder involving abnormalities in skeletal development and other health problems. It is a member of a group of related conditions called otopalatodigital spectrum disorders, which also includes otopalatodigital syndrome types 1 and 2, and frontometaphyseal dysplasia. In general, these disorders involve hearing loss caused by malformations in the tiny bones in the ears (ossicles), problems in the development of the roof of the mouth (palate), and skeletal abnormalities involving the fingers and/or toes (digits).

Melnick-Needles syndrome is usually the most severe of the otopalatodigital spectrum disorders. People with this condition are usually of short stature, have an abnormal curvature of the spine (scoliosis), partial dislocation (subluxation) of certain joints, and unusually long fingers and toes. They may have bowed limbs; underdeveloped, irregular ribs that can cause problems with breathing; and other abnormal or absent bones.

Characteristic facial features may include bulging eyes with prominent brow ridges, excess hair growth on the forehead, round cheeks, a very small lower jaw and chin (micrognathia), and misaligned teeth. One side of the face may appear noticeably different from the other (facial asymmetry). Some individuals with this disorder have hearing loss.

In addition to skeletal abnormalities, individuals with Melnick-Needles syndrome may have obstruction of the ducts between the kidneys and bladder (ureters) or heart defects.

Males with Melnick-Needles syndrome generally have much more severe signs and symptoms than do females, and in almost all cases die before or soon after birth.

How common is Melnick-Needles syndrome?

Melnick-Needles syndrome is a rare disorder; fewer than 100 cases have been reported worldwide.

What genes are related to Melnick-Needles syndrome?

Mutations in the FLNA gene cause Melnick-Needles syndrome.

The FLNA gene provides instructions for producing the protein filamin A, which helps build the network of protein filaments (cytoskeleton) that gives structure to cells and allows them to change shape and move. Filamin A binds to another protein called actin, and helps the actin to form the branching network of filaments that make up the cytoskeleton. Filamin A also links actin to many other proteins to perform various functions within the cell.

A small number of mutations in the FLNA gene have been identified in people with Melnick-Needles syndrome. These mutations are described as "gain-of-function" because they appear to enhance the activity of the filamin A protein or give the protein a new, atypical function. Researchers believe that the mutations may change the way the filamin A protein helps regulate processes involved in skeletal development, but it is not known how changes in the protein relate to the specific signs and symptoms of Melnick-Needles syndrome.

Read more about the FLNA gene.

How do people inherit Melnick-Needles syndrome?

This condition is inherited in an X-linked dominant pattern. A condition is considered X-linked if the mutated gene that causes the disorder is located on the X chromosome, one of the two sex chromosomes. The inheritance is dominant if one copy of the altered gene in each cell is sufficient to cause the condition. In most cases, males experience more severe symptoms of the disorder than females. A striking characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons.

Where can I find information about treatment for Melnick-Needles syndrome?

These resources address the management of Melnick-Needles syndrome and may include treatment providers.

• Gene Review: Otopalatodigital spectrum disorders

You might also find information on treatment of Melnick-Needles syndrome in Educational resources and Patient support.

Where can I find additional information about Melnick-Needles syndrome?

You may find the following resources about Melnick-Needles syndrome helpful. These materials are written for the general public.

• MedlinePlus - Health informationHealth Topic: Bone Diseases
• Educational resources - Information pagesOrphanet
• Patient support - For patients and families (2 links)

You may also be interested in these resources, which are designed for healthcare professionals and researchers.

• Gene Reviews - Clinical summary
• Gene Tests - DNA tests ordered by healthcare professionals
• PubMed - Recent literature
• OMIM - Genetic disorder catalog

What other names do people use for Melnick-Needles syndrome?

• Melnick-Needles osteodysplasty
• MNS
• osteodysplasty of Melnick and Needles

See How are genetic conditions and genes named? in the Handbook.

What if I still have specific questions about Melnick-Needles syndrome?

• See How can I find a genetics professional in my area? in the Handbook.
• Ask the Genetic and Rare Diseases Information Center.
• Submit your question to Ask the Geneticist.

Where can I find general information about genetic conditions?

The Handbook provides basic information about genetics in clear language.

• What does it mean if a disorder seems to run in my family?
• What are the different ways in which a genetic condition can be inherited?
• If a genetic disorder runs in my family, what are the chances that my children will have the condition?
• Why are some genetic conditions more common in particular ethnic groups?

These links provide additional genetics resources that may be useful.

• Genetics and health
• Resources for Patients and Families
• Resources for Health Professionals

What glossary definitions help with understanding Melnick-Needles syndrome?

actin ; atypical ; bulging eyes ; cell ; chromosome ; cytoskeleton ; dislocation ; duct ; dysplasia ; gene ; inheritance ; joint ; kidney ; malformation ; micrognathia ; mutation ; obstruction ; ossicle ; palate ; protein ; scoliosis ; sex chromosomes ; sign ; spectrum ; stature ; symptom ; syndrome ; trait ; ureter ; X-linked dominant

You may find definitions for these and many other terms in the Genetics Home Reference Glossary.