breasts and/or nipples, aplasia or hypoplasia of, 2

Breasts and/or nipples, aplasia or hypoplasia of, type 2, is an isolated congenital condition characterized primarily by underdevelopment or absence of breast tissue and related structures. It results from a pathogenic mutation in the PTPRF gene, which plays a role in cellular signaling and tissue development. This condition is present from birth, although precise prevalence estimates are not well established. Affected individuals may present with distinctive differences in breast and nipple formation as one of the primary features.

The clinical presentation of this condition centers on abnormalities in the development of the breasts and nipples. Commonly observed features include absent nipple, hypoplastic areola, and hypoplastic nipples, which are evident at birth. Aside from the primary breast findings, several facial and other physical characteristics have been noted in a significant proportion of cases; these include a highly arched eyebrow, anteverted nares, smooth philtrum, broad nasal tip, widely spaced teeth, and a small earlobe, each observed in approximately 30 to 79% of individuals. Additional features such as male urethral meatus stenosis, cryptorchidism, and bilateral single transverse palmar creases have also been reported. Not all individuals experience every feature, and severity varies considerably.

This condition is caused by a mutation in the PTPRF gene. The PTPRF gene plays an important role in cell signaling pathways that are vital during development, and its disruption leads to the congenital underdevelopment of breast and nipple structures. It is inherited in an autosomal recessive pattern, meaning that an affected individual has inherited two copies of the mutated gene, one from each parent. Families may consider genetic counseling to understand the implications of this inheritance pattern, as siblings of an affected child have a 25% chance of being affected if both parents are carriers.

Currently, management focuses on supportive care and symptom management, as no specific treatments have been approved for this condition. Treatment plans are highly individualized and often involve a multidisciplinary team to address the unique clinical features observed in each patient. Patients and families are encouraged to consult with healthcare providers to discuss the range of supportive options available and to determine what interventions may be most beneficial. Genetic counseling is also recommended to help families understand the inheritance pattern and implications for future family planning.

The long-term outlook for individuals with this condition is variable, with outcomes depending on the severity of the clinical features and the effectiveness of supportive interventions. With current standards of care, many individuals continue to lead active lives, and improvements in multidisciplinary management have helped to optimize quality of life. Outcomes described in medical literature continue to evolve as standards of care improve. Families are advised to seek ongoing genetic counseling and support from specialist healthcare providers to address any emerging concerns and to consider connecting with patient groups for additional guidance and community support.