Genital Abnormality - Hypospadia
Introduction
Hypospadias are the most common penis abnormality (1 in 300) and result from a failure of male urogenital folds to fuse in various regions, the normal process is described as virilization of the external genitalia. This in turn leads to resulting in a proximally displaced urethral meatus or opening. The cause is unknown, but suggested to involve many factors either indivdually or in combination including: familial inheritance, low birth weight, assisted reproductive technology, advanced maternal age, paternal subfertility and endocrine-disrupting chemicals.[1] Infants with hypospadias should not undergo circumcision.
Some Recent Findings
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Hypospadia Classification
The condition is classified by the general location of the relocated opening (meatus) and lack of fusion.
Hypospadia Classification | Meatus Opening | Image |
Anterior | on inferior surface of glans penis | A |
Coronal | in balanopenile furrow | B |
Distal | on distal third of shaft | C |
Penoscrotal | at base of shaft in front of scrotum | D |
Scrotal | on scrotum or between the genital swellings | E |
Perineal | behind scrotum or genital swellings | F |
Surgical Repair
Depending on the class of hypospadias there are a number of different surgical repair techniques including: orthoplasty or penile straightening, urethroplasty, meatoplasty and glanuloplasty, scrotoplasty (oscheoplasty) and skin coverage.
Maternal Factors
Data from a case-control study in Sweden and Denmark (2000 - 2005) identified a number of maternal factors that may be associated with hypospadias.[4]
- Maternal diet during pregnancy lacking both fish and meat - more than 4-fold increased risk
- Maternal obesity - more than 2-fold increased risk
- Maternal hypertension - 2.0-fold increased risk
- Maternal absence of nausea - 1.8-fold increased risk
- Maternal nausea in late pregnancy - also appeared to be positively associated with increased risk
Molecular Factors
- chromosomal abnormalities
- HOX, FGF, Shh - genes of penile development
- WT1, SRY - testicular determination
- luteinizing hormone (LH) receptor
- 5alpha reductase, androgen receptor - action of androgen
- CXorf6
- ATF3
Links: OMIM - CXorf6
Related Genetic Conditions
- X-linked isolated hypospadias-1 HYSP1 OMIM 300633
- X-linked isolated hypospadias-2 HYSP2 OMIM 300758
- X-linked isolated hypospadias-3 HYSP3 OMIM 146450
- Johanson-Blizzard syndrome[5] - hypospadias, failure to thrive, exocrine pancreatic deficiency, short stature and developmental delay, cutis aplasia on the scalp, aplasia of alae nasi, hypothyroidism, myxomatous mitral valve, and patent ductus arteriosus.
References
Reviews
Articles
Search Pubmed
June 2010 "Hypospadia" All (4698) Review (377) Free Full Text (413)
Search Pubmed: Hypospadia | Hypospadia Surgical Repair
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Cite this page: Hill, M.A. (2024, June 15) Embryology Genital Abnormality - Hypospadia. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Genital_Abnormality_-_Hypospadia
- © Dr Mark Hill 2024, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G