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Isolated congenital breast hypoplasia/aplasia(BNAH1)

MedGen UID:
Concept ID:
Congenital Abnormality
Synonym: Aplasia or hypoplasia of breasts and/or nipples
SNOMED CT: Amastia (271020004); Congenital absence of breast with absent nipple (271020004); Amazia (271020004)
Related gene: PTPRF
Monarch Initiative: MONDO:0015855
OMIM®: 113700
OMIM® Phenotypic series: PS113700
Orphanet: ORPHA180188


A rare breast malformation characterized by congenital absence of breast and nipple (amastia), or nipple or mammary gland (athelia or amazia, respectively). It can be unilateral or bilateral and may occur as an isolated malformation or be associated with a syndrome or cluster of other anomalies. [from ORDO]

Clinical features

From HPO
Choanal atresia
MedGen UID:
Concept ID:
Congenital Abnormality
Absence or abnormal closure of the choana (the posterior nasal aperture). Most embryologists believe that posterior choanal atresia results from a failure of rupture between the 35th and 38th day of fetal life of the partition which separates the bucconasal or buccopharyngeal membranes. The resultant choanal atresia may be unilateral or bilateral, bony or membranous, complete or incomplete. In over 90 per cent of cases the obstruction is bony, while in the remainder it is membranous. The bony type of atresia is commonly located 1-2 mm. anterior to the posterior edge of the hard palate, and the osseous septum varies in thickness from 1 to 10 mm. In the membranous form of choanal atresia the obstruction usually occurs further posteriorly. In approximately one third of cases the atresia is bilateral.
Absent nipple
MedGen UID:
Concept ID:
Congenital Abnormality
Congenital failure to develop, and absence of, the nipple.
Aplasia/Hypoplasia of the nipples
MedGen UID:
Concept ID:
Hypoplastic areola
MedGen UID:
Concept ID:
Underdevelopment of the areola, the circular area of pigmented skin surrounding the nipple.
Aplasia/Hypoplasia of the breasts
MedGen UID:
Concept ID:
Absence or underdevelopment of the breasts.

Term Hierarchy

CClinical test,  RResearch test,  OOMIM,  GGeneReviews,  VClinVar  

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