Other chromosome abnormalities, not elsewhere classified (Q99)
The ICD-10 code Q99 covers various chromosome abnormalities that do not fit into other specific categories. It includes unique genetic conditions such as chimerism, true hermaphroditism, fragile X chromosome syndrome, and a wide range of other specified and unspecified chromosomal anomalies.
This section is used to classify rare and complex chromosomal disorders. For example, Q99.0 identifies the chimera condition (46,XX/46,XY), where cells with two different genetic lines coexist. The code Q99.1 relates to the 46,XX true hermaphrodite condition, also known by terms like ovarian dysgenesis or pure gonadal dysgenesis 46,XX. Q99.2 is used for the fragile X chromosome, associated with fragile X syndrome and related intellectual disabilities. Q99.8 captures a vast variety of specified chromosomal abnormalities including maternal or paternal uniparental disomy and other rare syndromes, while Q99.9 represents unspecified chromosomal abnormalities. Understanding the ICD-10 codes for these conditions helps healthcare providers accurately document and communicate detailed genetic findings.
Clinical Terms
The following clinical terms provide additional context, helping users better understand the clinical background and common associations for each diagnosis listed in this section. Including related terms alongside ICD-10-CM codes supports coders, billers, and healthcare professionals in improving accuracy, enhancing documentation, and facilitating research or patient education.
Asthenozoospermia
A condition in which the percentage of motile sperm is abnormally low.
Autoimmune Lymphoproliferative Syndrome
Rare congenital lymphoid disorder due to mutations in certain Fas-Fas ligand pathway genes. Known causes include mutations in FAS, TNFSF6, NRAS, CASP8, and CASP10 proteins. Clinical features include LYMPHADENOPATHY; SPLENOMEGALY; and AUTOIMMUNITY.
Chimera
An individual that contains cell populations derived from different zygotes.
Fragile X Syndrome
A condition characterized genotypically by mutation of the distal end of the long arm of the X chromosome (at gene loci FRAXA or FRAXE) and phenotypically by cognitive impairment, hyperactivity, SEIZURES, language delay, and enlargement of the ears, head, and testes. INTELLECTUAL DISABILITY occurs in nearly all males and roughly 50% of females with the full mutation of FRAXA. (From Menkes, Textbook of Child Neurology, 5th ed, p226)
Proteolysis Targeting Chimera
Bifunctional molecules that are designed to recruit E3 UBIQUITIN LIGASE to a specific target protein. Proteolysis targeting chimera consist of a target protein ligand connected via a linker to an E3 ligand. They promote association of E3 with specific target proteins tagged for degradation via the PROTEASOME.
Radiation Chimera
An organism whose body contains cell populations of different genotypes as a result of the TRANSPLANTATION of donor cells after sufficient ionizing radiation to destroy the mature recipient's cells which would otherwise reject the donor cells.
Teratozoospermia
Conditions in which sperm show abnormal morphology.
Transplantation
Transference of a tissue or organ from either an alive or deceased donor, within an individual, between individuals of the same species, or between individuals of different species.
Transplantation Chimera
An organism that, as a result of transplantation of donor tissue or cells, consists of two or more cell lines descended from at least two zygotes. This state may result in the induction of donor-specific TRANSPLANTATION TOLERANCE.
Transplantation Tolerance
An induced state of non-reactivity to grafted tissue from a donor organism that would ordinarily trigger a cell-mediated or humoral immune response.
Uniparental Disomy
The presence in a cell of two paired chromosomes from the same parent, with no chromosome of that pair from the other parent. This chromosome composition stems from non-disjunction (NONDISJUNCTION, GENETIC) events during MEIOSIS. The disomy may be composed of both homologous chromosomes from one parent (heterodisomy) or a duplicate of one chromosome (isodisomy).
