Homeobox expressed in ES cells 1, also known as homeobox protein ANF, is a homeobox protein that in humans is encoded by the HESX1 gene. [5]
Expression of HEX1 and HESX1 marks the anterior visceral endoderm of the embryo. The AVE is an extra-embryonic tissue, key to the establishment of the anterior-posterior body axis.
Mutations in the HESX1 gene are associated with some cases of septo-optic dysplasia [6] or Pickardt-Fahlbusch syndrome. [7]
Septo-optic dysplasia (SOD), known also as de Morsier syndrome, is a rare congenital malformation syndrome that features a combination of the underdevelopment of the optic nerve, pituitary gland dysfunction, and absence of the septum pellucidum . Two or more of these features need to be present for a clinical diagnosis — only 30% of patients have all three. French-Swiss doctor Georges de Morsier first recognized the relation of a rudimentary or absent septum pellucidum with hypoplasia of the optic nerves and chiasm in 1956.
Thyroxine-binding globulin (TBG) is a globulin protein that in humans is encoded by the SERPINA7 gene. TBG binds thyroid hormones in circulation. It is one of three transport proteins (along with transthyretin and serum albumin) responsible for carrying the thyroid hormones thyroxine (T4) and triiodothyronine (T3) in the bloodstream. Of these three proteins, TBG has the highest affinity for T4 and T3 but is present in the lowest concentration relative to transthyretin and albumin, which also bind T3 and T4 in circulation. Despite its low concentration, TBG carries the majority of T4 in the blood plasma. Due to the very low concentration of T4 and T3 in the blood, TBG is rarely more than 25% saturated with its ligand. Unlike transthyretin and albumin, TBG has a single binding site for T4/T3. TBG is synthesized primarily in the liver as a 54-kDa protein. In terms of genomics, TBG is a serpin; however, it has no inhibitory function like many other members of this class of proteins.
Growth hormone deficiency (GHD), or human growth hormone deficiency, is a medical condition resulting from not enough growth hormone (GH). Generally the most noticeable symptom is that an individual attains a short height. Newborns may also present low blood sugar or a small penis size. In adults there may be decreased muscle mass, high cholesterol levels, or poor bone density.
Hypopituitarism is the decreased (hypo) secretion of one or more of the eight hormones normally produced by the pituitary gland at the base of the brain. If there is decreased secretion of one specific pituitary hormone, the condition is known as selective hypopituitarism. If there is decreased secretion of most or all pituitary hormones, the term panhypopituitarism is used.
Thyroid hormone resistance describes a rare syndrome in which the thyroid hormone levels are elevated but the thyroid stimulating hormone (TSH) level is not suppressed, or not completely suppressed as would be expected. The first report of the condition appeared in 1967. Essentially this is decreased end organ responsiveness to thyroid hormones. A new term "impaired sensitivity to thyroid hormone" has been suggested in March 2014 by Refetoff et al.
Isolated hypogonadotropic hypogonadism (IHH), also called idiopathic or congenital hypogonadotropic hypogonadism (CHH), as well as isolated or congenital gonadotropin-releasing hormone deficiency (IGD), is a condition which results in a small subset of cases of hypogonadotropic hypogonadism (HH) due to deficiency in or insensitivity to gonadotropin-releasing hormone (GnRH) where the function and anatomy of the anterior pituitary is otherwise normal and secondary causes of HH are not present.
Corticosteroid 11-β-dehydrogenase isozyme 2 also known as 11-β-hydroxysteroid dehydrogenase 2 is an enzyme that in humans is encoded by the HSD11B2 gene.
POU domain, class 1, transcription factor 1 , also known as POU1F1, is a transcription factor for growth hormone.
Gonadotropin-releasing hormone receptor is a protein that in humans is encoded by the GNRHR gene.
The human gene SRD5A2 encodes the 3-oxo-5α-steroid 4-dehydrogenase 2 enzyme, also known as 5α-reductase type 2 (5αR2), one of three isozymes of 5α-reductase.
HSD3B2 is a human gene that encodes for 3beta-hydroxysteroid dehydrogenase/delta(5)-delta(4)isomerase type II or hydroxy-delta-5-steroid dehydrogenase, 3 beta- and steroid delta-isomerase 2. It is expressed principally in steroidogenic tissues and is essential for steroid hormone production. A notable exception is the placenta, where HSD3B1 is critical for progesterone production by this tissue.
Thyroid hormone receptor beta (TR-beta) also known as nuclear receptor subfamily 1, group A, member 2 (NR1A2), is a nuclear receptor protein that in humans is encoded by the THRB gene.
Homeobox protein prophet of PIT-1 is a protein that in humans is encoded by the PROP1 gene.
Growth hormone 2 (GH2), also known more commonly as placental growth hormone (PGH) or as growth hormone variant (GH-V), is a protein that in humans is encoded by the GH2 gene. It is produced by and secreted from the placenta during pregnancy, and becomes the predominant form of growth hormone (GH) in the body during this time. Its cogener is growth hormone 1 (GH1), or pituitary growth hormone.
LIM/homeobox protein Lhx3 is a protein that in humans is encoded by the LHX3 gene.
LIM/homeobox protein Lhx4 is a protein that in humans is encoded by the LHX4 gene.
Autoimmune hypophysitis is defined as inflammation of the pituitary gland due to autoimmunity.
Thyroid stimulating hormone, beta also known as TSHB is a protein which in humans is encoded by the TSHB gene.
Kowarski syndrome describes cases of growth failure, despite the presence of normal or slightly high blood growth hormone by radioimmunoassay (RIA-GH) and low serum IGF1, and who exhibit a significant increase in growth rate following recombinant GH therapy.
To date, at least twenty five different genes have been implicated in causing gonadotropin-releasing hormone (GnRH) deficiency conditions such as Kallmann syndrome (KS) or other forms of congenital hypogonadotropic hypogonadism (CHH) through a disruption in the production or activity of GnRH. These genes involved cover all forms of inheritance, and no one gene defect has been shown to be common to all cases, which makes genetic testing and inheritance prediction difficult.