Neurocristopathies are a class of pathologies in vertebrates, including humans, that result from abnormal expression, migration, differentiation, or death of neural crest cells (NCCs) during embryonic development. NCCs are cells derived from the embryonic cellular structure called the neural crest. Abnormal NCCs can cause a neurocristopathy by chemically affecting the development of the non-NCC tissues around them. They can also affect the development of NCC tissues, causing defective migration or proliferation of the NCCs. There are many neurocristopathies that affect many different types of systems. Some neurocristopathies result in albinism (piebaldism) and cleft palate in humans. Various pigment, skin, thyroid, and hearing disorders, craniofacial and heart abnormalities, malfunctions of the digestive tract, and tumors can be classified as neurocristopathies. This classification ties a variety of disorders to one embryonic origin.
Sheldon Clark Reed helped establish the profession of genetic counseling in the US during the twentieth century. In 1947 Reed coined the term genetic counseling to describe the interaction of a doctor explaining to a patient the likelihood of passing a certain trait to their offspring. With physicians being able to test for genetic abnormalities like cystic fibrosis, Reed helped trained individuals give patients the tools to make informed decisions. In 1955 Reed published the book Counseling in Medical Genetics. Reed educated patients about how certain genetically transmitted traits could adversely affect their offspring and provided options for remedying those effects.
Truman William Brophy developed a cleft palate surgical repair, later called the Brophy Operation, in the late nineteenth century US. The procedure improved facial aesthetics and speech in cleft palate patients. A cleft palate occurs during development when the palatal bones in the roof of the mouth don't completely fuse, leaving an opening, or cleft, in the upper lip and mouth. Brophy's cleft repair used compression inside and outside of the mouth to push the palatal bones into normal alignment shortly after birth. Brophy advocated surgery on newborns with cleft palates as soon as possible after birth, which met with opposition in the late nineteenth and early twentieth centuries when medical professionals did not operate on infants for non-life threatening conditions. However, Brophy's successful operations convinced many doctors to adopt his technique.
Noninvasive fetal aneuploidy detection technology allows for the detection of fetal genetic conditions, specifically having three chromosomes, a condition called aneuploidy, by analyzing a simple blood sample from the pregnant woman. Dennis Lo and Rossa Chiu researched methods of detection of aneuploidies in the early twenty-first century. Their research has been specifically applied to three trisomies, trisomy twenty-one known as Down syndrome, trisomy eighteen known as Edwards Syndrome, and trisomy thirteen known as Patau Syndrome. Prior to the ability to detect fetal DNA in a pregnant woman’s blood, physicians performed amniocentesis or chorionic villus sampling, two techniques that increase the risk of spontaneous abortion. Noninvasive detection of trisomy twenty-one, eighteen, and thirteen technology allows for a more accurate and safer detection of those conditions than methods available before.
Jeffrey Weinzweig and his team, in the US at the turn of the twenty-first century, performed a series of experiments on fetal goats to study the feasibility of repairing cleft palates on organisms still in the womb. Weinzweig , a plastic surgeon who specialized in cleft palate repair, and his team developed a method to cause cleft palates in fetal goats that are similar to clefts that occur in human fetuses. Using their goat congenital model, the team developed a method to repair a congenital cleft palate in utero, or in the womb. The resultant goat newborns had fully developed palates without scarring and with minimal functional impairment. The researchers recommended that surgeons use their repair methods in humans to decrease the incidence of speech impairment commonly associated with cleft palate patients.
Smile Train is a non-profit organization that Brian Mullaney and Charles Wang founded in 1999 in New York City, New York, that provides resources and trains medical staff in over ninety countries to give free surgeries to children in need of cleft repair. Clefts are birth defects that affect one in 700 children all over the world. They occur when the roof of the mouth, or palate, the lip, or both have a gap or split, because the tissues and bones did not fuse properly during fetal development. Surgeons typically repair clefts within the first year of life because clefts can often cause problems with eating, speaking, breathing, and hearing. Beyond providing cleft surgeries, Smile Train also supports the needs of children with clefts with services such as speech therapy, dental care, and psychological and nutritional support. Smile Train helps provide better access to cleft surgery and care for thousands of children worldwide, which improves the quality of life for people born with the developmental condition.
In May 2017, Alice Lee, Fiona E. Gibbon, and Kimberley Spivey published “Children’s Attitudes Toward Peers With Unintelligible Speech Associated With Cleft Lip and/or Palate,” hereafter “Children’s Attitudes,” in The Cleft Palate Craniofacial Journal. About one in every 1600 babies in the US is born with both cleft lip and cleft palate, which are birth defects that can also occur independently. Those birth defects occur when the lip or roof of the mouth, also called the palate, do not fully develop during pregnancy. The condition often results in speech difficulties, even after children undergo surgery to repair their cleft palate. “Children’s Attitudes” was one of the first articles investigating how different age groups of children judged their peers with speech difficulties who had undergone a cleft palate repair surgery. The authors found that peers’ attitudes towards speech problems tended to be negative. “Children’s Attitudes” concludes that judgment from peers can negatively affect children with speech difficulties and argues that increased public awareness of speech difficulties may reduce barriers that children with those difficulties face.
Pierre Franco was a surgeon in Europe in the sixteenth century who developed a variety of surgical procedures, including some to repair hernias, cleft lips, and bladder stones. A hernia occurs when an internal organ protrudes through a weak spot in a muscle or tissue, typically in the abdomen, which can cause severe pain, nausea, and vomiting. A cleft lip is a congenital abnormality where the tissues of the upper lip and roof of the mouth do not form properly as the fetus develops during pregnancy, causing problems with eating and speaking. Bladder stones are hard masses of minerals that build up from a person’s urine and form in their bladder, often causing pain or bleeding during urination. Franco described the congenital origin of the cleft lip and was one of the first to develop a repairing procedure for hernias without the removal of genitals. As of 2024, surgeons have continued to innovate upon many of Franco’s surgical procedures, including those to repair hernias and cleft lips, to help children born with congenital defects and other patients in need of surgery.