Wright Dyck syndrome

A condition characterised by a sensory neuropathy associated with deafness and dementia.

Wrinkly skin syndrome

A very rare genetic disorder characterized by wrinkly skin that occurs primarily on the palms and soles but can occur on other parts of the body. The condition is also associated with various other abnormalities.

Wyburn Mason’s syndrome

A rare genetic condition mainly involving enlarged brain blood vessels and skin and eye abnormalities.

X chromosome- monosomy Xp22 pter

X chromosome, monosomy Xp22 pter: A condition that is characterised by the occurrence of only one X chromosome in the genotype of an individual.

X chromosome- monosomy Xq28

X chromosome, monosomy Xq28 (medical condition): A condition that is characterised by the occurrence of only one X chromosome in the genotype of an individual.

X chromosome- trisomy 26-28

X chromosome, trisomy 26-28: A condition characterised by the duplication of the long arm of chromosome X.

X chromosome- trisomy Xp3

X chromosome, trisomy Xp3: A condition characterised by the duplication of the long arm of chromosome X.

X chromosome- trisomy Xq

X chromosome, trisomy Xq: A condition characterised by the duplication of the long arm of chromosome X

X chromosome- trisomy Xq25

X chromosome, trisomy Xq25: A condition characterised by the duplication of the long arm of chromosome X.

X fragile site folic acid type

X fragile site folic acid type: A fragile X syndrome that is characterised by mental retardation and developmental delay.

X-linked adrenal hypoplasia congenita

X-linked congenital adrenal hypoplasia (medical condition): A genetic disorder which affects the body tissues that produce hormones . It is characterized by underdeveloped adrenal glands which results adrenal insufficiency and hypogonadotrophic hypogonadism.

X-linked adrenoleukodystrophy

X-linked adrenoleukodystrophy (also known as Adrenoleukodystrophy, ALD, X-ALD, adrenomyeloneuropathy, AMN, Siemerling–Creutzfeldt disease or bronze Schilder disease) is a disorder of peroxisomal fatty acid beta oxidation which results in the accumulation of very long chain fatty acids in tissues throughout the body. The most severely affected tissues are the myelin in the central nervous system, the adrenal cortex and the Leydig cells in the testes. Clinically, ALD is a heterogenous disorder, presenting with several distinct phenotypes, and no clear pattern of genotype-phenotype correlation. As an X-linked disorder, ALD presents most commonly in males, however approximately 50% of heterozygote females show some symptoms later in life. Approximately two-thirds of ALD patients will present with the childhood cerebral form of the disease, which is the most severe form. It is characterized by normal development in early childhood, followed by rapid degeneration to a vegetative state. The other forms of ALD vary in terms of onset and clinical severity, ranging from adrenal insufficiency to progressive paraparesis in early adulthood (this form of the disease is typically known as adrenomyeloneuropathy).

X-Linked Agammaglobulinemia

X-linked agammaglobulinema is a genetic condition that affects the immune system and occurs almost exclusively in males. Affected individuals have very few B cells in the body, which produce antibodies called immunoglobulins that help protect the body against infection. Those with this condition are more susceptible to infections because their body makes very few of these antibodies.This condition is inherited in an X-linked recessive pattern and is caused by mutations in the BTK gene. 

It occurs in a frequency of about 1 in 100,000 male newborns, and has no ethnic predisposition. XLA is treated by infusion of human antibody. Treatment with pooled gamma globulin cannot restore a functional population of B cells, but it is sufficient to reduce the severity and number of infections due to the passive immunity granted by the exogenous antibodies.

X-Linked Cobalamin Disorder

Obtained from foods such as milk, eggs, fish and meat, B 12 is essential to human health because it helps the body convert food into fuel. It's vital to the nervous system and for making red blood cells.

Derivatives of vitamin B12 (cobalamin) are essential cofactors for enzymes required in intermediary metabolism. Defects in cobalamin metabolism lead to disorders characterized by the accumulation of methylmalonic acid and/or homocysteine in blood and urine. 

X-linked Hypohidrotic Ectodermal Dysplasia

X-linked hypohidrotic ectodermal dysplasia (XLHED) is a rare genetic disorder. Children born with XLHED have a reduced ability to sweat (hypohidrosis), abnormally shaped and missing teeth (hypodontia), and fine sparse hair (hypotrichosis). There are a number of additional features of XLHED, which may include dry eyes, eczema, asthma, and dry mucous membranes in the mouth and nose.


In the first years of life, children with XLHED are at risk for severe medical complications. These complications are most often associated with their inability to sweat, which can lead to their bodies overheating. Children with XLHED also have reduced mucous secretion and may be more prone to respiratory infections. Throughout childhood the focus of care may shift to chronic skin issues, medical management, and self-esteem challenges of severe hypodontia—missing and pointed teeth. Dentures may be prescribed as early as age 2-3 years to enhance feeding and growth and to begin to address what are often life-long psychosocial issues.


The worldwide incidence of XLHED is estimated to be between 4 to 10/100,000 male births (as many as 200 births annually). Additionally, about 50% of XLHED-carrier females (approximately 400 births annually) are estimated to have symptoms that would warrant therapeutic intervention.


X-linked ichthyosis

X-linked ichthyosis: A rare genetic skin disorder occurring in males only and resulting from an inborn error of metabolism (deficiency of the enzyme steroid sulfatase).

X-linked Juvenile Retinoschisis

X-linked juvenile retinoschisis (XLRS) is a genetic ocular disease characterized by reduced visual acuity in males due to juvenile macular degeneration.

X-linked lymphoproliferative syndrome

X-linked lymphoproliferative syndrome (XLP) is an inherited disorder of the immune system that affects males. XLP is characterized by an abnormal immune response to infection with the Epstein-Barr virus (EBV). This is a common virus in the normal population, which causes infectious mononucleosis (“mono or kissing disease”). In normal individuals, EBV causes no long lasting ill effects. In individuals with X-linked lymphoproliferative syndrome, there is a mutation (mistake) in the XLP gene, SH2D1A/DSHP/SAP. This gene helps control the immune response to an EBV infection. As a result, males with XLP who are exposed to the EBV virus can have life-threatening symptoms. Patients with the disorder, in the absence of an acute EBV infection, are also subject to immune system problems, including recurrent infections and an unusual susceptibility to B-cell lymphomas. The diagnosis is confirmed by mutation detection (laboratory tests looking for a mistake in the XLP gene).

Source: http://www.stjude.org/stjude/v/index.jsp?vgnextoid=c3ac061585f70110VgnVCM1000001e0215acRCRD&vgnextchannel=bc4fbfe82e118010VgnVCM1000000e2015acRCRD

X-linked mental retardation and macro-orchidism

Mental retardation, X-linked - macrocephaly - macro-orchidism: A rare disorder characterized by mental retardation, enlarged testes and a large head. Not all patients will exhibit all of these symptoms.

X-linked mental retardation craniofacial abnormal microcephaly club

X-linked mental retardation craniofacial abnormal microcephaly club: A rare inherited disorder characterized by mental retardation, small head, club foot and facial and skull abnormalities. The condition is inherited in a X-linked manner and thus only males present with the full severity of the symptoms. Female carriers may be mildly symptomatic or have no symptoms at all.