Other abnormalities include deformation of ribs, absence of pectoralis muscle, hypoplasia or abnormalities of breast and subcutaneous tissue. Patients may also have webbed fingers on one hand, short bones in the forearm or sparse underarm hair. Al Awadi/Raas-Rothschild syndrome
Al Awadi/Raas-Rothschild syndrome is a rare genetic disorder. Symptoms are often associated with absence or maldevelopment of skeletal part of limbs. Scalp-ear-nipple syndrome
As the name suggests, Scalp-ear-nipple syndrome is characterized by congenital absence of skin, abnormalities of scalp, malformation of ear structures, and undeveloped nipples. Mechanism
Mammary glands are arranged in breasts of the primates to produce milk for feeding offspring. They are enlarged and modified sweat glands. In the embryological development, mammary glands firstly appear after six weeks of pregnancy in the form of ectodermal ridges. The ectodermal ridge grows thicker and compresses to form mesoderm. As the proliferation persists, mesodermal layer continues to form clusters. The clusters grow and become lobules. At the same time, the clusters also form a pit, which protrudes to generate the nipples. Impairment in some of these processes may cause aplasia of the breast tissue, which may result in amastia.For example, in normal condition, mammary ridge (milk line) would extend from the bilateral axillary tail to the inguinal region. If this extension does not occur in normal way, the breast would not develop successfully.Amastia may also be caused by the inability of producing parathyroid hormone related protein. The absence of this protein will disrupt the normal development of mammary gland.
Amastia refers to a rare clinical anomaly in which both internal breast tissue and the visible nipple are absent on one or both sides. It affects both men and women. Amastia can be either isolated (the only medical condition) or comorbid with other syndromes, such as ectodermal dysplasia, syndactaly (Polands syndrome) and lipoatrophic diabetes. This abnormality can be classified into various types, and each could result from different pathologies. Amastia differs from amazia and athelia. Amazia is the absence of one or both mammary glands but the nipples remain present, and athelia is the absence of one or both nipples, but the mammary gland remains.Amastia is presumably due to failure of embryologic (before birth) mammary ridge development or incomplete involution. People with amastia often suffer from ectodermal defects, which include various syndromes such as cleft palate, isolated pectoral muscle and abnormal formation of the arms.Treatment for female amastia particularly includes psychological guidance and breast reconstruction. Because there is no breast tissue, breastfeeding is not possible. If amastia only appears on one side, then it is possible to breastfeed on the other side. Often, people with amastia decide against treatment. Classification
Amastia can be either iatrogenic or congenital. The congenital amastia are further divided into syndromic type and non-syndromic type respectively. As the definition suggests, syndromic amastia is often associated with obvious symptoms. The common case is hypoplasia of ectodermal tissue, such as hair and skin defects. On the other hand, non-syndromic amastia, shows no defects in body parts other than breast.